SEC Form PRE 14A filed by PLUS THERAPEUTICS Inc.

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Filed by a Party other than the Registrant  ☐

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July [•], 2025

To Our Stockholders:

In the last year, Plus Therapeutics made significant progress in advancing our therapeutic pipeline. Furthermore, in mid-2024, we acquired CNSide^TM a novel cerebrospinal fluid assay platform that enables the detection and management of central nervous system cancers.

Our lead investigational radiotherapeutic drug, REYOBIQ^TM, is currently being evaluated for use in patients with three types of central nervous system cancers. specifically leptomeningeal metastases (LM), pediatric brain cancer (PBC) and recurrent glioblastoma (rGBM). Earlier in 2025, we completed the ReSPECT-LM safety trial and are now enrolling patients in a dose optimization trial to find a safe and effective dose of REYOBIQ we can then take into a US registrational trial. Also in 2025, the FDA cleared Plus to begin enrolling patients in Phase 1/2a trial for children with brain cancer and we anticipate to begin enrolling soon. Our pediatric trial builds on our successful Phase 1 adult glioblastoma trial. The results of the trial show substantial safety margins, signs of efficacy and was published earlier in 2025 in the prestigious medical journal Nature Communications. Our glioblastoma Phase 2 trial, ReSPECT-GBM, continues to enroll patients in 2025. Each of these trials continues to benefit from approximately $25M in active grant support.

Since the acquisition of CNSide, we have laid the ground work for a successful relaunch of CNSide here in the US. Those preparatory activities are largely complete and we plan to reintroduce the product in Texas in the second half of 2025 and extend that launch to all 50 states. Furthermore, in the past year, we have published a number of scientific articles showing clinical value of CNSide, its core test now recemented in the National Comprehensive Cancer Center Guidelines, completed and presented the FORSEE clinical trial results clearly showing its clinical value, built out a centralized testing laboratory in Houston, validated key commercial elements such as pricing and reimbursement and hired an experienced diagnostics executive team to lead the CNSide commercial subsidiary. Our conviction is higher than ever that CNSide uniquely fills a $6B hole in the CNS cancer diagnostic space.

Finally, we have taken a number of actions to capitalize the company beyond our existing grant funding that will help bridge our capital requirements from our current position to diagnostic revenue and ultimately to FDA approval of REYOBIQ. The past year for Plus has been noteworthy for material clinical progress and a game-changing acquisition that was both opportunistic and strategic that we think will soon reward our stockholders. On behalf of our employees, management and directors, I would like to express our deep appreciation to our stockholders and partners for their help and support in 2024 and beyond.

 

Dear Plus Therapeutics, Inc. Stockholder:

You are cordially invited to attend the 2025 Annual Meeting of the Stockholders of Plus Therapeutics, Inc. (the “Annual Meeting”). The Annual Meeting will be held on August 7, 2025, commencing at 9:00 a.m. (Eastern Time), and will be a completely virtual meeting of stockholders.

The items of business for the meeting are to:

The Board recommends that stockholders (a) elect each board member nominee; and (b) vote to approve items (ii), (iii), (iv), and (v).

In light of our successful virtual annual meetings of stockholders in the past four years, the Annual Meeting will be held only via live webcast again this year. We believe that the virtual meeting format also expands stockholder access, participation and improves communications, and we encourage you to attend online and participate.

You will be able to attend and participate in the Annual Meeting online, vote your shares electronically, and submit your questions prior to and during the meeting by visiting: www.virtualshareholdermeeting.com/PSTV2025. To vote at the meeting, you must have your control number that is shown on your proxy card. There will not be a physical meeting location and you will not be able to attend the annual meeting in person.

Only stockholders of record at the close of business on June 18, 2025, are entitled to notice of and to vote at the Annual Meeting. For ten (10) days prior to the Annual Meeting, a complete list of stockholders entitled to vote at the Annual Meeting will be available at the Corporate Secretary’s office at 2710 Reed Road Suite 160, Houston, TX 77002. We expect to commence mailing these proxy materials to our security holders on or about [ ], 2025.

You are cordially invited to attend the Annual Meeting live via the Internet. It is important that your shares are represented at the Annual Meeting. Even if you plan to attend the Annual Meeting live via the Internet, we hope that you will promptly vote by dating, signing and returning the enclosed proxy card or vote via the Internet or by telephone. This will not limit your ability to attend or vote during the Annual Meeting.

Plus Therapeutics, Inc.

Houston, Texas, USA

July [•], 2025

This Proxy Statement on Schedule 14A (the “Proxy Statement”) contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), which statements involve substantial risks and uncertainties. Forward-looking statements generally relate to future events or our future financial or operating performance and may include statements concerning, among other things, our business strategy, our governance initiatives and impacts of our compensation program.

In some cases, you can identify forward-looking statements by words such as “anticipate,” “believe,” “consider,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “plan,” “predict,” “should” or “will” or the negative or plural of these words or other similar terms or expressions. All statements other than statements of historical fact are forward-looking statements, which speak only as of the date they are made, and are not guarantees of future performance.

These forward-looking statements are not guarantees of future performance and involve a number of assumptions, risks and uncertainties that could cause actual results to differ materially from expected results. As a result, you should not put undue reliance on any forward-looking statement. These forward-looking statements are included throughout this Proxy Statement. Factors that could cause our actual results to differ materially from those expressed or implied in such forward-looking statements include, but are not limited to, to changes in global, regional or local political, economic, business, competitive, market, regulatory and other factors, many of which are beyond our control, as well as the risk factors discussed in the “Risk Factors” section of our Annual Report on Form 10-K, which was filed with the Securities and Exchange Commission (the “SEC”) on March 31, 2025 (the “2024 Annual Report”), and in other subsequent filings with the SEC. Should one or more of these risks or uncertainties materialize, or should any of our assumptions prove to be incorrect, our actual results may vary in material respects from what we may have expressed or implied by these forward-looking statements. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and we caution that you should not place undue reliance on any of our forward-looking statements. Any forward-looking statement made by us in this Proxy Statement speaks only as of the date on which we make it. We undertake no obligation to publicly update any forward-looking statement, whether as a result of new information, future developments or otherwise, except as may be required by applicable securities laws. You should read this Proxy Statement with the understanding that our actual future results, performance, and events and circumstances may be materially different from what we expect.

Our Board is soliciting your proxy to vote at the Annual Meeting, for the purposes set forth in this Proxy Statement. This Proxy Statement includes information that we are required to provide to you under the rules of the SEC and that is designed to assist you in voting your shares. The Annual Meeting will be held virtually via a live webcast on the Internet on Thursday, August 7, 2025 at 9:00 a.m. (Eastern Time). For purposes of attendance at the Annual Meeting, all references in this Proxy Statement to “present in person” or “in person” shall mean virtually present at the Annual Meeting.

We have fixed the close of business on June 18, 2025 as the record date for the determination of the stockholders entitled to notice of and to vote at the Annual Meeting (the “Record Date”). Only holders of record of shares of our common stock (“Common Stock”) on that date are entitled to notice of and to vote at the Annual Meeting.

You will be able to attend and participate in the Annual Meeting online, vote your shares electronically, and submit your questions prior to and during the meeting by visiting: www.virtualshareholdermeeting.com/PSTV2025. To vote at the meeting, you must have your control number that is shown on your proxy card. There will not be a physical meeting location and you will not be able to attend the annual meeting in person.

In this Proxy Statement, we refer to Plus Therapeutics Inc. as “Plus,” the “Company, “we,” “us” or “our” and the board of directors of Plus as “our Board.” Our 2024 Annual Report accompanies this Proxy Statement. Information contained on, or that can be accessed through, our website is not intended to be incorporated by reference into this Proxy Statement and references to our website address in this Proxy Statement are inactive textual references only.

A proxy statement is a document that the SEC regulations require us to give you when we ask you to provide a proxy to vote your shares at the Annual Meeting. Among other things, this Proxy Statement describes the proposals on which stockholders will be voting and provides information about us. You are viewing, or have received, these proxy materials because our Board is soliciting your proxy to vote your shares of Common Stock at the Annual Meeting. This proxy statement includes information that we are required to provide to you under the rules of the SEC and that is designed to assist you in voting your shares. Instructions regarding how you can vote are contained on the proxy card included in the proxy materials. We will use the proxies received in connection with the Annual Meeting to:

Our Board recommends that you vote “FOR” each director nominees named in Proposal 1, “FOR” the approval, for purposes of complying with Nasdaq Listing Rule 5635(d), of the potential issuance and sale of (i) up to $50,000,000 of the Company’s Common Stock and (ii) up to $1,000,000 of Commitment Shares pursuant to the Lincoln Park Purchase Agreement in Proposal 2, “FOR” the Reverse Stock Split Proposal in Proposal 3, “FOR” the approval, on an advisory basis, of the compensation of our named executive officers in Proposal 4 and “FOR” the approval of the amendment and restatement of the 2020 Stock Incentive Plan in Proposal 5.

A proxy is your legal designation of another person to vote the stock you own. That designee is referred to as a proxy holder. Designation of a particular proxy holder can be effected by completion of a written proxy card, or by voting via the Internet or by telephone. If you return a proxy card, or vote by phone or Internet, our President and Chief Executive Officer, Marc H. Hedrick, M.D., and our Chief Financial Officer, Andrew Sims, will act as your designated proxy holder at the Annual Meeting.

The Annual Meeting will be a virtual meeting of stockholders, which will be conducted exclusively by webcast. You are entitled to participate in the Annual Meeting only if you were a stockholder of the Company as of the close of business on June 18, 2025, or if you hold a valid proxy for the Annual Meeting.

No physical meeting will be held. You will be able to attend the Annual Meeting online and submit your questions during the meeting by visiting www.virtualshareholdermeeting.com/PSTV2025. Stockholders attending the Annual Meeting will be afforded the same rights and opportunities to participate as they would at an in-person meeting. You also will be able to vote your shares online by attending the Annual Meeting webcast. To participate in the Annual Meeting, you will need the sixteen- (16) digit control number provided on your proxy card. For more information, review the information included on your proxy card, or the instructions that accompanied your proxy materials. If you are the beneficial owner of your shares, your control number is included with your voting instruction card and voting instructions received from your brokerage firm, bank or other nominee.

The Annual Meeting will begin promptly at 9:00 a.m. (Eastern Time) on August 7, 2025. We encourage you to access the meeting prior to the start time, leaving ample time for the check in. Please follow the instructions in this Proxy Statement and on your proxy card.

We will hold a live question and answer session, during which we intend to answer appropriate questions submitted by stockholders during the Annual Meeting that are pertinent to the Company and the Annual Meeting matters. If you would like to submit a question during the Annual Meeting, you may log in at www.virtualshareholdermeeting.com/PSTV2025 using your control number, type your question into the “Ask a Question” field, and click “Submit.” To help ensure that we have a productive and efficient meeting, and in fairness to all stockholders in attendance, you will also find posted our rules of conduct for the Annual Meeting when you log in prior to its start. We will answer as many questions, submitted in accordance with our rules of conduct, as practicable in the time allotted.

You are a stockholder of record, or a “registered holder,” if your shares are registered in your own name through our transfer agent. If you have a stock certificate, you are also a stockholder of record. You are a beneficial owner of our stock in street name if you hold your shares through a broker, bank or other third-party institution (in this situation, the banks, brokers, etc., are the stockholders of record). The vast majority of our stockholders hold their shares in street name.

Stockholder of Record: Shares Registered in Your Name. Stockholders who are a registered holder may vote by virtually attending the proxy meeting, submitting votes electronically over the Internet, by telephone or by completing and mailing a proxy card. The website identified on the proxy card provides specific instructions on how to vote electronically over the Internet. Those stockholders who receive a paper proxy by mail, and who elect to vote by mail, should complete and return the mailed proxy card in the prepaid and addressed envelope that was enclosed with the proxy materials. Stockholders who vote over the Internet or by telephone need not return a proxy card or voting instruction form by mail, but may incur costs, such as usage charges, from telephone companies or Internet service providers. Even if you have submitted a proxy before the meeting, you may still attend online and vote during the meeting. In such case, your previously submitted proxy will be disregarded. For more information, see the question below titled “How can I change my vote or revoke my proxy after submitting a proxy?”

Beneficial Owner: Shares Held on Your Behalf by a Brokerage Firm, Bank, or Other Nominee. If you are the beneficial owner of stock held in street name, follow the instructions from your broker, bank or other nominee to vote your shares.

Stockholders who have previously elected to access our proxy materials and annual report electronically over the Internet will continue to receive a Notice with information on how to access the proxy information and voting instructions.

Only proxy cards and voting instruction forms that have been signed, dated and timely returned and only proxies that have been timely voted electronically or by telephone will be counted in the quorum and voted.

You may also vote your shares at the Annual Meeting. If you are a registered holder you must join live online at www.virtualshareholdermeeting.com/PSTV2025. The webcast will start at 9:00 a.m. (Eastern Time). You may vote and submit questions while attending the meeting online. You will need the control number included on your proxy card (if you received a printed copy of the proxy materials) to vote during the meeting.

If you receive more than one email notice, proxy card or voting instruction form because your shares are held in multiple accounts or registered in different names or addresses, please vote your shares held in each account to ensure that all of your shares will be voted.

A representative of an independent inspector of election, who we retained, will tabulate and certify the votes.

We will have technicians ready to assist you with any technical difficulties you may have accessing the Annual Meeting. If you encounter any difficulties accessing the Annual Meeting during the check-in or meeting time, please call the technical support number that will be posted at www.virtualshareholdermeeting.com/PSTV2025.

A list of our stockholders of record as of the close of business on the Record Date will be made available at the Corporate Secretary’s office at 2710 Reed Road, Suite 160, Houston, TX 77002, for ten days before the Annual Meeting.

The Record Date for the Annual Meeting is June 18, 2025. The Record Date is established by our Board as required by Delaware General Corporation Law. Owners of our Common Stock at the close of business on the Record Date are entitled to receive notice of the meeting and to vote at the Annual Meeting and any adjournment, continuation or postponement of the Annual Meeting.

If you are a stockholder of record, you may revoke or change your vote or revoke your proxy at any time before the final vote at the Annual Meeting in any one of the following ways:

We recommend that you also submit your proxy, voting instructions or vote in advance of the Annual Meeting through the Internet so that your vote will be counted if you later decide not to attend the Annual Meeting

If you are a beneficial owner and your shares are held in “street name” on your behalf by a brokerage firm, bank or other nominee, you should follow the instructions provided by that nominee.

Your most recent proxy card, Internet or telephone proxy is the one that is counted. Your attendance at the Annual Meeting by itself will not revoke your proxy unless you give written notice of revocation to the Corporate Secretary before your proxy is voted or you vote electronically at the Annual Meeting.

In voting on the election of director nominees to serve until the 2026 Annual Meeting of Stockholders, stockholders may vote in favor of each nominee or may withhold votes as to each nominee. In addition, if any other candidates are properly nominated at the Annual Meeting, stockholders of record who attend the Annual Meeting could vote for the other candidates. Directors are elected by a plurality vote, which means that the six (6) nominees receiving the most affirmative votes will be elected. Stockholders are not entitled to cumulative voting rights with respect to the election of directors. Only votes “FOR” will affect the outcome.

In voting on the approval, for purposes of complying with Nasdaq Listing Rule 5635(d), the potential issuance and sale of (i) up to Fifty Million Dollars ($50,000,000) of our Common Stock and (ii) up to One Million Dollars ($1,000,000) of Commitment Shares, pursuant to the Lincoln Park Purchase Agreement, stockholders

may vote in favor of or against the proposal, or may abstain from voting on this proposal. The affirmative vote of a majority of the Common Stock having voting power present at the Annual Meeting or represented by proxy at the Annual Meeting is required to approve this proposal. Abstentions will be counted as present for purposes of determining a quorum and are considered shares present and entitled to vote and thus will have the effect of a vote “AGAINST” this proposal.

In voting on the approval of the Reverse Stock Split Proposal, stockholders may vote in favor of or against the proposal, or they may abstain from voting on the proposal. The affirmative vote of a majority of all votes cast by the holders of shares of Common Stock entitled to vote will be required for approval. Abstentions and broker non-votes, if any, will have no effect on the outcome of this proposal.

In voting on the approval, on an advisory basis, of the compensation of our named executive officers, stockholders may vote in favor of or against the proposal, or may abstain from voting on this proposal. The affirmative vote of a majority of the Common Stock having voting power present at the Annual Meeting or represented by proxy at the Annual Meeting is required to approve this proposal. Abstentions will be counted as present for purposes of determining a quorum and are considered shares present and entitled to vote and thus will have the effect of a vote “AGAINST” this proposal.

This vote is advisory, and therefore not binding on the Board. Although the vote is non-binding, the Board will review the voting results, seek to determine the cause or causes of any significant negative voting, and take them into consideration when making future decisions regarding executive compensation programs.

In voting on the approval of the fifth amendment and restatement of the Plus Therapeutics, Inc. 2020 Stock Incentive Plan, stockholders may vote in favor of or against the proposal, or they may abstain from voting on the proposal. The affirmative vote of a majority of the Common Stock having voting power present at the Annual Meeting or represented by proxy at the Annual Meeting is required to approve this proposal. Abstentions will be counted as present for purposes of determining a quorum and are considered shares present and entitled to vote and thus will have the effect of a vote “AGAINST” this proposal.

If you are a stockholder of record and do not vote through the Internet, by completing a proxy card, by telephone or online during the Annual Meeting, your shares will not be voted.

If you properly complete and return a proxy card or vote by Internet or by telephone, the designated proxy holders will vote your shares as you have directed. If you sign a proxy card but do not make specific choices or if you vote by Internet or telephone but do not make specific choices, the designated proxy holders will vote your shares as recommended by the Board as follows:

With respect to the election of directors, if any nominee is unable or declines to serve, or for good cause will not serve, as a director at the time of the Annual Meeting, an event that is not currently anticipated, the designated proxy holders will have the express discretionary authority to vote for a replacement nominee designated by our Board, and proxies will be voted for any nominee designated by our Board to fill the vacancy.

If you are a beneficial owner and do not instruct your brokerage firm, bank or other nominee how to vote your shares, your shares will be considered “uninstructed” and the question of whether your nominee will still be able to vote your shares depends on whether, pursuant to stock exchange rules, the particular proposal is deemed to be a “routine” matter. Brokerage firms, banks and other nominees can use their discretion to vote “uninstructed” shares with respect to matters that are considered to be “routine,” but not with respect to “non-routine” matters. Under applicable rules and interpretations, “non-routine” matters are matters that may substantially affect the rights or privileges of stockholders, such as elections of directors (even if not contested), mergers, stockholder proposals, executive compensation and certain corporate governance proposals, even if management-supported. Accordingly, your brokerage firm, bank or other nominee may vote your shares on Proposal 3, which is considered “routine,” without your instructions. Your brokerage firm, bank or other nominee may not, however, vote your shares on Proposal 1, Proposal 2, Proposal 4, or Proposal 5, without your instructions, because they are considered “non-routine,” which would result in a “broker non-vote” and your shares would not be counted as having been voted on these proposals. Please instruct your brokerage firm, bank or other nominee as to how to vote your shares to ensure that your vote will be counted.

If you are a beneficial owner of shares held in street name, and you do not plan to attend the Annual Meeting, in order to ensure your shares are voted in the way you would prefer, you must provide voting instructions to your brokerage firm, bank or other nominee by the deadline provided in the materials you receive from your nominee.

As discussed above, when a beneficial owner of shares held in “street name” does not give instructions to the brokerage firm, bank or other nominee holding the shares as to how to vote on matters deemed to be “non-routine,” the brokerage firm, bank or other nominee cannot vote the shares. These unvoted shares are counted as “broker non-votes.”

Abstentions and broker non-votes will be counted as present for purposes of determining a quorum. An abstention occurs when a stockholder chooses to “ABSTAIN” from voting on a matter. As discussed above, a broker non-vote occurs when a broker, bank, or other stockholder of record, in nominee name or otherwise, exercising fiduciary powers, submits a proxy for the Annual Meeting, but does not vote on a particular proposal because that holder does not have discretionary voting power with respect to that proposal and has not received voting instructions from the beneficial owner. Under the rules that govern brokers who are voting with respect to shares held in street name, brokers have the discretion to vote those shares on routine matters, but not on non-routine matters. We expect the proposal regarding a reverse stock split to be a routine matter, and therefore, broker non-votes are not expected to exist with respect to such proposal. We expect the other proposals described in this proxy statement to be non-routine. Brokers and nominees do not have discretionary voting power over these non-routine proposals and, therefore, broker non-votes may exist with respect to these proposals. Broker non-votes will not affect the outcome of any of these non-routine matters that are being voted on at the Annual Meeting, provided that a quorum is obtained. However, we strongly encourage you to submit your proxy and exercise your right to vote as a stockholder to ensure your shares are voted in the manner in which you want them voted.

We will pay the entire cost of the solicitation of proxies for the Annual Meeting. This includes preparation, assembly, printing and mailing of the Notice, this Proxy Statement and any other information we send to stockholders. In addition, we may supplement our efforts to solicit your proxy in the following ways:

We will not pay directors, officers or other regular employees any additional compensation for their efforts to supplement our proxy solicitation. We anticipate banks, brokerage houses and other custodians, nominees and fiduciaries will forward solicitation material to the beneficial owners of shares of Common Stock entitled to vote at the Annual Meeting and that we will reimburse those persons for their out-of-pocket expenses incurred in performing such services.

For business to be conducted at the Annual Meeting, a quorum of stockholders must be present. A quorum exists when the holders of at least 33¹⁄₃% of the shares of our Common Stock issued, outstanding and entitled to vote are represented at the Annual Meeting.

On June 18, 2025, there were 60,490,101 shares of our Common Stock outstanding and entitled to one vote. Holders of our Common Stock as of the close of business on the Record Date will be entitled to vote at the Annual Meeting. Thus, based on the holders as of June 18, 2025, we estimate that the holders of approximately 20,163,367 shares of Common Stock would need to be present in person or represented by proxy at the Annual Meeting to have a quorum.

Your shares will be counted as present only if you submit a valid proxy (or one is submitted on your behalf by your brokerage, bank or other nominee), vote by telephone, through the Internet or if you vote online during the Annual Meeting. Abstentions and broker non-votes will be counted towards the quorum requirement. If there is no quorum, the chairperson of the Annual Meeting or holders of a majority of the voting power of the shares present at the Annual Meeting may adjourn the Annual Meeting to another date.

You may cast one vote for every share of our Common Stock that you owned on the Record Date. As of the Record Date, June 18, 2025, there were 60,490,101 shares of Common Stock outstanding, each of which is entitled to one vote.

Although we do not know of any business to be considered at the Annual Meeting other than the proposals described in this Proxy Statement, if any additional business is presented at the Annual Meeting, your proxy gives authority to the designated proxy holders to vote on such matters according to their best judgment.

No. The Notice identifies the items to be voted on at the Annual Meeting, but you cannot vote by marking the Notice and returning it. The Notice provides instructions on how to vote by proxy in advance of the Annual Meeting through the Internet, by telephone, using a printed proxy card or online during the Annual Meeting.

We will publish the final voting results in a current report on Form 8-K, which we expect to file with the SEC within four business days of the Annual Meeting. If the final voting results are unavailable in time to file a current report on Form 8-K with the SEC within four business days after the Annual Meeting, we intend to file a Form 8-K to disclose the preliminary results and, within four business days after the final results are known, we will file an additional current report on Form 8-K with the SEC to disclose the final voting results.

The Company does not have a policy about directors’ attendance at the Annual Meeting, but directors are encouraged to attend. All directors and director nominees at the time other than Robert Lenk and Greg Petersen attended the 2024 Annual Meeting of Stockholders.

We are not aware of any items, other than those referred to in the accompanying Notice, which may properly come before the meeting or other matters incident to the conduct of the meeting. As to any other item or proposal that may properly come before the meeting, it is intended that proxies will be voted in the discretion of the proxy holders.

The Company’s website contains, among other corporate governance documents, the Company’s Corporate Governance Guidelines and Codes of Business Conduct & Ethics. To view these documents, go to www.plustherapeutics.com, click “For Investors” then “Governance” and then “Corporate Governance Materials.” To view the Company’s committee charters, go to www.plustherapeutics.com, click “For Investors” then “Governance” and then “Board Committees.” To view the Company’s SEC filings, including Forms 3, 4 and 5 filed by the Company’s directors and executive officers, go to www.plustherapeutics.com, click on “For Investors” then “Reports & Filings.” The 2024 Annual Report includes our consolidated financial statements for the year ended December 31, 2024. We have furnished the 2024 Annual Report to all stockholders.

The names of the members of the Board and Plus’s director nominees, their respective ages, their positions with Plus and other biographical information as of June 18, 2025, are set forth below. Except for Marc H. Hedrick, M.D., our Chief Executive Officer, President and a director, there are no other family relationships among any of our directors or executive officers.

In addition to the qualifications, qualities and skills that are necessary to meet U.S. state and federal legal, regulatory and Nasdaq Stock Market, LLC (“Nasdaq”) listing requirements and the provisions of our Certificate of Incorporation, as amended (the “Certificate of Incorporation”), amended and restated Bylaws (the “Bylaws”), corporate governance guidelines (the “Corporate Governance Guidelines” and charters of our Board’s committees, our Board will consider appropriate factors in evaluating director nominees, including: character, judgment, leadership, business acumen, diversity of background and perspective, skills, age, gender, ethnicity, professional experience, knowledge of or experience in the pharmaceutical industry, sufficient time to devote to Plus’s affairs and commitment to represent the long-term interests of Plus’s stockholders.

Although we do not have a formal diversity policy, our Board does consider gender and ethnic diversity as factors in its evaluation of candidates for director nominations. There are no other pre-established qualifications, qualities or skills at this time that any particular director nominee must possess and nominees are not discriminated against on the basis of race, religion, national origin, sexual orientation, disability or any other basis proscribed by law. The Nominating and Corporate Governance Committee does not assign specific weights to any particular criteria, nor has it adopted specific requirements. Rather, the Board believes that the backgrounds and qualifications of the directors, considered as a group, should provide a composite mix of experience, knowledge and abilities that will allow the Board to fulfill its responsibilities. The goal of the Nominating and Corporate Governance Committee is to assemble a Board that brings a variety of skills derived from high quality businesses and professional experience.

Our Board is composed of a diverse group of professionals in their respective fields. Many of the current directors have or have held senior leadership experience at major domestic and international companies. In these positions, they have also gained experience in core management skills, such as strategic and financial planning, public company financial reporting, compliance, risk management, leadership development, and international business experience. Most of our directors also have experience serving on boards of directors and board committees of other public companies in the pharmaceutical industry, and have an understanding of corporate governance practices and trends, different business processes, challenges, and strategies. Further, our directors also have other experience that makes them valuable members, such as medical knowledge and research experience, which provides insight into strategic and operational issues faced by us.

The Nominating and Corporate Governance Committee and the Board believe that the above-mentioned attributes, along with the leadership skills and other experiences of our Board members described below, provide us with a diverse range of perspectives and judgment necessary to guide our strategies and monitor their execution.

Set forth below is biographical information for the director nominees. This includes information regarding each director’s experience, qualifications, attributes or key skills that led our Board to recommend them for service on our Board.

Richard J. Hawkins. Mr. Hawkins has served on our Board since December 2007 and has been the Chairman of our Board since January 2018. In 1982, Mr. Hawkins founded Pharmaco, a clinical research organization, where he served as its Chairman, President and Chief Executive Officer until 1991 when it merged with the predecessor of PPD-Pharmaco. In 1992, Mr. Hawkins co-founded Sensus Drug Development Corporation, a privately-held company focused on the development of drugs to treat endocrine disorders, which developed and received regulatory approval for SOMAVERT, a growth hormone antagonist approved for the treatment of acromegaly, which is now marketed by Pfizer, Inc. (NYSE:PEE), where he served as Chairman until 2000. In 1994, Mr. Hawkins co-founded Corning Biopro, a contract protein manufacturing firm, where he served on its board until Corning BioPro’s sale to Akzo-Nobel, N.V. (OTC:AKZOY), a publicly-held producer of paints, coatings and specialty chemicals, in 2000. In September 2003, Mr. Hawkins founded LabNow, Inc., a privately held company that develops lab-on-a-chip sensor technology, where he served as the Chairman and Chief Executive Officer until October 2009. In February 2011, Mr. Hawkins became Chief Executive Officer, and held the positions of Chief Executive Officer, President and Chairman of Lumos Pharma, Inc. (Nasdaq: LUMO) until the time of its sale in December 2023. Additionally, Mr. Hawkins served on the board of SciClone Pharmaceuticals, Inc. (HKD: SCLN), a publicly-held specialty pharmaceutical company, from October 2004 through December 2017. He also served on the Presidential Advisory Committee for the Center for Nano and Molecular Science and Technology at the University of Texas at Austin, and was inducted into the Hall of Honor for the College of Natural Sciences at the University of Texas. Mr. Hawkins is a member of the National Ernst & Young Entrepreneur of the Year Hall of Fame. Mr. Hawkins graduated cum laude with a B.S. in Biology from Ohio University, where he later received the Ohio University Konneker Medal, the highest award given to a faculty member or former student, for entrepreneurial excellence. We believe Mr. Hawkins’s qualifications to serve on our Board include his executive experience working with life sciences companies, his extensive experience in pharmaceutical research and development, his knowledge, understanding and experience in the regulatory development and approval process, and his service on other public company boards and committees.

Marc H. Hedrick, M.D. Dr. Hedrick joined the Company in October 2002 as its Chief Scientific Officer. In May 2004, he was appointed as President of the Company and in April 2014, he was appointed as its Chief Executive Officer. Dr. Hedrick has served as a member of our board of directors (the “Board”) since joining the Company in October 2002. Previously, Dr. Hedrick served in a number of executive leadership positions, including President and Chief Executive Officer of StemSource from 2001 to 2003 and Chief Scientific Officer and Medical Director of Macropore Biosurgery from 2002 to 2004. Dr. Hedrick has also served as a board member for a number of public and private companies since 2000. Prior to his corporate career, Dr. Hedrick was Associate Professor of Surgery and Pediatrics at the University of California, Los Angeles (“UCLA”). While at UCLA, Dr. Hedrick’s academic research received both National Institutes of Health funding as well as private and public capitalization and was widely acknowledged through scientific publications and the media. Dr. Hedrick also has first-hand experience as a physician, practicing general, vascular and craniofacial surgery. Dr. Hedrick has a medical degree from The University of Texas Southwestern Medical School and a Master of Business Administration from the UCLA Anderson School of Management and is a trained general, vascular and plastic surgeon. We believe Dr. Hedrick’s qualifications to serve on our Board include his executive, financial, governance and operational leadership experience in medical and pharmaceutical product development.

Howard Clowes. Mr. Clowes has served on our Board since April 1, 2020. From January 2005 until he retired as a lawyer in December 2018, Mr. Clowes was a partner in the law firm DLA Piper (US) LLC. From 1982 until the formation of DLA Piper in 2005, he was an associate and then a partner in the predecessor firms of DLA Piper, holding various management positions, including serving on its board of directors and its compensation committee. Mr. Clowes served on the board of Equalize Health and as chair of its governance committee from January 2018 to May 2022, and serves on the board of AFRAC, each of which are nonprofit corporations focused on global healthcare. Mr. Clowes served on the board of the Law Foundation of Silicon Valley, a

non-profit organization located in San Jose, California, that provides free legal services to Silicon Valley residents in need, from 2008 until December 2018, during which he served in various positions, including President of its board of directors, and Chair of its Strategic Planning and Chief Executive Officer Search Committee. From 2017 to 2021, Mr. Clowes served as a Lecturer at the University of California, Berkeley School of Law, teaching a course in International Business Negotiations. Mr. Clowes earned his J.D. at U.C. Berkeley, his B.A. in Experimental Psychology at U.C. Santa Barbara, and in 2023, Mr. Clowes received his National Association of Corporate Directors Directorship Certification. We believe Mr. Clowes’ qualifications to serve on the Board include his extensive experience as a lawyer, advising boards of directors and their audit, compensation and corporate governance committees on a wide range of matters, his experience with a wide range of transactions and his experience serving on various boards of directors.

Robert Lenk, Ph.D. Dr. Lenk has served on our Board since April 1, 2020. Since 2016, he has served as President of Lenk Pharmaceuticals, LLC, providing consulting services to clients in the pharmaceuticals industry. Dr. Lenk co-founded the Liposome Company, in Princeton, New Jersey in 1981 (now part of Elan Pharmaceuticals). After the Liposome Company went public, he co-founded Argus Pharmaceuticals, a drug delivery company focused on cancer and infectious diseases, in 1989 and served as Vice President of Research & Development, until it merged with two other companies to become Aronex Pharmaceuticals. From 1995 to 2003, Dr. Lenk served as President and Chief Executive Officer of Therapeutics 2000, Inc. which was later sold to Coller Capital. Dr. Lenk joined Luna Innovations in 2004 where he served as President of its Nanoworks Division until 2010. In 2010, Dr. Lenk joined MediVector, Inc. as its Chief Science Officer until 2016, when he started Lenk Pharmaceuticals, LLC, a pharmaceutical development consulting company, where he currently works. He also currently serves on the board of PoP Biotechnology, a private company that develops vaccines and cancer therapies based on proprietary porphyrin liposome nanoparticle technology. Dr. Lenk received both his PhD and BSc. From the Massachusetts Institute of Technology. We believe Dr. Lenk’s qualifications to serve on our Board include his broad experience in translating research candidates into products, especially in the fields of nanotechnology and liposomal drug products.

Kyle Guse, Esq., MBA, CPA (inactive). Mr. Guse was appointed to our Board in April 2025. Mr. Guse has been serving as the Chief Legal Officer of DDC Enterprise Ltd. (NYSE:DDC), an NYSE-American-listed international consumer foods company, since September 2023. From January 2013 to May 2023, Mr. Guse was Chief Financial Officer, General Counsel and Secretary of Atossa Therapeutics, Inc. (Nasdaq, ATOS), a Nasdaq-listed biotechnology company developing treatments and prevention for breast cancer. Mr. Guse’s experience includes 30 years of counseling innovative, rapid growth companies through all aspects of finance, corporate governance, securities laws and commercialization, with a particular focus on M&A and capital market transactions. Mr. Guse has practiced law at several of the largest international law firms, including from January 2012 through January 2013 as a partner at Baker Botts LLP and, prior to that, from October 2007 to January 2012, as a partner at McDermott Will & Emery LLP. Before working at McDermott Will & Emery, Mr. Guse served as a partner at Heller Ehrman LLP. Mr. Guse began his career as an accountant at Deloitte and he is an inactive Certified Public Accountant and member of the bars of California and Washington. Mr. Guse earned a B.S. in business administration and an M.B.A. from California State University, Sacramento, and a J.D. from Santa Clara University School of Law. We believe that Mr. Guse’s extensive legal and business expertise in corporate finance and capital markets, corporate governance and mergers and acquisitions qualifies him to serve on our Board.

An van Es-Johansson, M.D. Dr. van Es-Johansson has served on our Board since January 1, 2020. Dr. van Es-Johansson served as the Chief Medical Officer for AlzeCure Pharma, a Swedish pharmaceutical company with a primary focus on Alzheimer’s disease, from September 2018 through March 1, 2021, following which she has continued to serve AlzeCure Pharma as a Senior Advisor beginning in March 2021. Since 2021 she has been a Senior Advisor for Sinfonia AB, a Swedish pharmaceutical company with focus on neuroscience. From May 2005 to September 2018, Dr. van Es-Johansson served in a range of executive roles of increasing responsibility at Sobi, an international rare disease company headquartered in Stockholm, Sweden, including as Vice President and Head of EMENAR Medical Affairs for Specialty Care and Partner Products from March 2013 to January 2018. Prior to her time at Sobi, Dr. van Es-Johansson served in leadership positions within large pharmaceutical and smaller biotechnology companies, including Roche, Pharmacia, Eli Lilly, Active Biotech and BioStratum. From 2004 to 2016, she was a member of the Scientific Advisory Board of Uppsala Bio and currently serves on the board of directors of Savara, Inc. (Nasdaq: SVRA), Lumos Pharma, Inc. (Nasdaq: LUMO) and privately held Agendia BV. She also served on the board of directors at BioInvent International AB (Nasdaq: OMX Stockholm: BINV), from June 2016 to February 2021; on the board of directors of Alzecure AB (NASDAQ OMX Stockholm: ALZCUR), from 2017-2020; on the board of directors

of Medivir AB (Nasdaq OMX Stockholm: MVIR) from 2019-2022; and on the board of directors of IRLAB AB (Nasdaq OMX Stockholm: IRLAB) from May 2022 to February 2023. Dr. van Es-Johansson received a M.D. from Erasmus University, Rotterdam, The Netherlands. We believe Dr. van Es- Johansson’s qualifications to serve on our Board include her extensive medical knowledge and experience in the pharmaceutical industry.

Our directors are elected for a term of one (1) year and until their respective successors are elected and qualified, or until their earlier resignation, disqualification, or removal.

There are no family relationships among any of the directors or executive officers.

Our Common Stock is listed on the Nasdaq Capital Market and under the listing rules of Nasdaq, subject to specified exceptions, independent directors must comprise a majority of a listed company’s board of directors, and each member of a listed company’s audit, compensation and nominating and corporate governance committees must be independent. Under Nasdaq listing rules, a director will only qualify as an “independent director” if, among other things, the listed company’s board of directors affirmatively determines that the director does not have a relationship which, in the opinion of the listed company’s board of directors, would interfere with the exercise of independent judgment in carrying out the responsibilities of a director.

Our Board reviews the independence of each director. This review is based primarily on responses of the directors to questions in a directors’ and officers’ questionnaire regarding employment, business, familial, compensation and other relationships with Plus and our management. Our Board has determined that no transactions or relationships existed that would disqualify any of our directors under the Nasdaq rules or would require disclosure under SEC rules, with the exception of Marc H. Hedrick, M.D., our President and Chief Executive Officer, because of his current employment relationship with Plus. In making these determinations, our Board considered the current and prior relationships that each non-employee director has with us and all other facts and circumstances our Board deemed relevant in determining their independence, including the beneficial ownership of our securities by each non-employee director and the transactions described in the section titled “Certain Relationships and Related Transactions.”

We currently separate the roles of Chief Executive Officer and Chairman of the Board. Our President and Chief Executive Officer is responsible for setting the strategic direction for our company and the day-to-day leadership and performance of our Company, while the Chairman of our Board presides over meetings of the Board, including executive sessions of the Board. Separating the duties of the Chairman from the duties of the Chief Executive Officer allows our Chief Executive Officer to focus on our day-to-day business, while allowing the Chairman to lead the Board in its fundamental role of providing advice to and independent oversight of management. Specifically, our Chairman runs meetings of our independent directors and assists with other corporate governance matters. Our Board believes that this structure ensures a greater role for the independent directors in the oversight of our company and active participation of the independent directors in setting agendas and establishing priorities and procedures for the work of our Board. Our Board believes that we have an appropriate leadership structure for us at this time which demonstrates our commitment to good corporate governance. Although the roles of Chairman and Chief Executive Officer are currently separate, our Nominating and Corporate Governance Committee and Board believe it is appropriate for our Chief Executive Officer to serve as a member of our Board.

Risk is inherent with every business and how well a business manages risk can ultimately determine its success. We face a number of risks, including those described under “Risk Factors” in our Annual Report on Form 10-K for the year ended December 31, 2024, and in our other filings with the SEC.

Our Board is actively involved in oversight of the key risks that could affect us. Our Board oversees our risk management processes directly and through its committees. Our management is responsible for risk management on a day-to-day basis and our Board of directors and its committees oversee the risk management activities of management. Our Board believes that risk management is an important part of establishing, updating and executing on Plus’s business strategy. Our Board, as a whole and at the committee level, has oversight responsibility relating to risks that could affect our corporate strategy, business objectives, compliance, operations, financial condition and performance. Our Board focuses its oversight on the most significant risks facing our company and oversees our risk management processes to identify, prioritize, assess, manage and mitigate those risks, which in turn supports the achievement of organizational objectives, improves long-term organizational performance and enhances stockholder value, while mitigating and managing identified risks. A fundamental part of our approach to risk management is not only understanding the most significant risks we face as a company and the necessary steps to manage those risks, but also deciding what level of risk is appropriate for our company. Our Board plays an integral role in guiding management’s risk tolerance and determining an appropriate level of risk. In addition, members of our senior management team attend our quarterly board meetings and are available to address any questions or concerns raised by the board on risk management and any other matters. Our Board believes that full and open communication between management and the Board is essential for effective risk management and oversight.

While our full Board has overall responsibility for evaluating key business risks, our committees monitor and report to our Board on certain risks. The Compensation Committee is responsible for overseeing the management of risks relating to our human capital and executive compensation plans and arrangements. The Audit Committee is responsible for overseeing the management of risks relating to accounting matters, financial reporting, and cybersecurity. The Nominating and Corporate Governance Committee is responsible for overseeing the management of risks associated with the independence of our Board and potential conflicts of interest. Although each committee is responsible for evaluating certain risks and overseeing the management of such risks, the entire Board is regularly informed about the primary risks associated with our business, as well as the key risk areas monitored by its committees. We believe that our Board’s leadership structure supports effective risk management because it allows independent directors at the board level and on our committees to exercise oversight over management.

Our Board is committed to effective corporate governance and has adopted a wide range of practices and procedures that promote effective Board oversight. For example:

Our Board may establish the authorized number of directors from time to time by resolution. Our Board currently consists of six (6) members.

No stockholder has any special rights regarding the election or designation of members of our Board. There is no contractual arrangement by which any of our directors are appointed to our Board. Our current directors will continue to serve as directors until the Annual Meeting and until their successor is duly elected, or if sooner, until their earlier death, resignation or removal.

Our Board held eight (8) meetings during 2024. No member of our Board attended fewer than seventy-five (75%) of the aggregate of (a) the total number of meetings of the Board (held during the period for which he or she was a director) and (b) the total number of meetings held by all committees of the Board on which such director served (held during the period that such director served). Members of our Board are invited and

encouraged to attend our annual meeting of stockholders. In 2024, all members of our Board at the time attended the 2024 Annual Meeting of Stockholders other than Robert Lenk and Greg Petersen.

In order to promote open discussion among non-management directors, and as required under applicable Nasdaq rules, our Board conducts executive sessions of non-management directors during each regularly scheduled Board meeting and at such other times, if requested by a non-management director. In 2024, the non-management directors met in executive session four (4) times. The non-management directors provide feedback to executive management, as needed, promptly after the executive session. Dr. Hedrick does not participate in such sessions. As Chairman of our Board, Mr. Hawkins presides over meetings of our independent directors without management present.

Our Board has established three standing committees: an Audit Committee; a Compensation Committee; and a Nominating and Corporate Governance Committee. The composition and responsibilities of each of these committees of our Board are described below. Members serve on these committees until their resignation or until otherwise determined by our Board. Our Board may establish other committees as it deems necessary or appropriate from time to time. The composition and functioning of all of our committees comply with all applicable requirements of the Sarbanes-Oxley Act, Nasdaq and SEC rules and regulations.

Each committee has adopted a written charter, which Board committees’ charters are available on our website at https://ir.plustherapeutics.com/governance/board-committees. The following table provides membership and meeting information for the fiscal year ended December 31, 2024 for each of the committees of our Board. Each Board member attended 75% or more of the aggregate number of meetings of the standing committee on which she or he served, held during the last fiscal year for which she or he was a committee member.

The Board has determined that each member of each standing committee meets the applicable Nasdaq rules and regulations regarding “independence” and each member is free of any relationship that would impair his or her individual exercise of independent judgment with regard to the Company. Each Board member attended 75% or more of the aggregate number of meetings of the standing committee on which she or he served, held during the last fiscal year for which she or he was a committee member.

Below is a description of each committee of our Board.

Our Audit Committee currently consists of Mr. Clowes, Dr. van Es-Johansson and Mr. Guse, who serves as Chairperson of the Audit Committee. The Board has determined that all members of the Audit Committee satisfied the independence requirements under Nasdaq listing standards and Rule 10A-3(b)(1) of the Exchange Act. The Board has determined that Mr. Guse is an “audit committee financial expert” within the meaning of SEC regulations. Each member of our Audit Committee can read and understand fundamental financial statements in accordance with applicable requirements. In arriving at these determinations, the Board has examined each Audit Committee member’s scope of experience and the nature of their employment. No member of the Audit Committee simultaneously serves on the audit committees of more than three (3) public companies, and no member of our Audit Committee has participated in the preparation of the financial statements of Plus at any time during the past three (3) years.

The primary purpose of the audit committee is to discharge the responsibilities of our Board with respect to our corporate accounting and financial reporting processes, systems of internal control and financial-statement audits, and to oversee our independent registered accounting firm. Specific responsibilities of our Audit Committee as provided in the Audit Committee Charter include:

Our Compensation Committee currently consists of Mr. Guse and Mr. Clowes, who serves as the committee’s Chairperson. Our Board has determined that both Mr. Guse and Mr. Clowes are independent under Nasdaq listing standards and are “non-employee directors” as defined in Rule 16b-3 promulgated under the Exchange Act.

The primary duties and responsibilities of our Compensation Committee as provided in the Compensation Committee Charter include, among other things, overseeing our compensation policies, plans and programs and determine the compensation to be paid to our executive officers, directors and other senior management, as appropriate.

Specific responsibilities of our Compensation Committee include:

See the sections titled “Executive Compensation” and “Director Compensation” for a description of our processes and procedures for the consideration and determination of our executive officers and directors compensation.

Our Nominating and Corporate Governance Committee currently consists of Mr. Clowes, Dr. Lenk, and Dr. van Es-Johansson, each of whom our Board has determined is independent under the Nasdaq listing standards, a non-employee director and free from any relationship that would interfere with the exercise of his or her independent judgment. The Chairperson of our Nominating and Corporate Governance Committee is Dr. van Es-Johansson.

Specific responsibilities of our Nominating and Corporate Governance Committee as provided in the Nominating and Corporate Governance Committee Charter include, among others:

Stockholders may contact an individual director, the Board as a group, or a specified Board committee or group, including the independent directors as a group, by the following means:

Each communication should specify the applicable addressee or addressees to be contacted as well as the general topic of the communication. The Chairman of the Board will initially receive and process communications before forwarding them to the addressee. Communications also may be referred to other departments within the Company. The Chairman of the Board generally will not forward to the directors a communication that he determines to be primarily commercial in nature or related to an improper or irrelevant topic, or that requests general information about us.

We have adopted a Code of Business Conduct and Ethics that applies to all our directors, officers and employees, including our principal executive officer, principal financial officer and principal accounting officer. This Code of Business Conduct and Ethics has been posted on our website at www.plustherapeutics.com. To the extent required by SEC rules, we intend to post amendments to this code, or any waivers of its requirements, on our website at https://ir.plustherapeutics.com/governance/corporate-governance-materials. To date, there have been no waivers under our Code of Business Conduct and Ethics.

Under our Insider Trading and Communications Policy, our directors, officers, employees, consultants and contractors (and each such individual’s family members, other members of a person’s household and entities controlled by a person covered by this policy, as described in the policy) are prohibited from engaging in the following transactions at any time: (i) engaging in short sales of our securities; (ii) trading in put options, call options or other derivative securities involving our securities on an exchange or in any other organized market; (iii) engaging in hedging or monetization transactions involving our securities, including through the use of financial instruments such as prepaid variable forwards, equity swaps, collars and exchange funds; and (iv) holding our securities in a margin account or otherwise pledging our securities as collateral for loan.

The Board has adopted Corporate Governance Guidelines, which addresses matters such as the Board’s core responsibilities and duties and the Board’s composition and compensation. The guidelines are also intended to align the interests of directors and management with those of our stockholders. The Corporate Governance Guidelines are available on our website at https://ir.plustherapeutics.com/governance/corporate-governance-materials.

Our Board has adopted the Plus Therapeutics, Inc. Incentive Compensation Recovery Plan, a policy for recovery of erroneously awarded compensation (the “Clawback Policy”), in accordance with the Nasdaq listing standards and Rule 10D-1 under the Exchange Act, which applies to our current and former executive officers. Under the Clawback Policy, we are required to recoup the amount of any erroneously awarded compensation on a pre-tax basis, within a specified lookback period, in the event of any Accounting Restatement (as defined in the Clawback Policy), subject to limited impracticability exceptions. Covered restatements include both a restatement to correct an error that is material to previously issued financial statements or that would result in a material misstatement if the error were corrected in the current period or left uncorrected in the current period. The amount required to be recovered is the excess of the amount of incentive-based compensation received over the amount that otherwise would have been received had it been determined based on the restated financial measure. The Clawback Policy is overseen and administered by the Compensation Committee. The full text of the Clawback Policy was included as Exhibit 97.1 to our 2023 Annual Report, filed with the SEC on March 5, 2024.

Section 16(a) of the Exchange Act requires our executive officers and directors to file initial reports of ownership and reports of changes in ownership with the SEC and to furnish us with copies of all Section 16(a) forms they file.

Based solely on our review of the copies of such reports filed with the SEC and written representations from the reporting person that no other reports were required during the fiscal year ended December 31, 2024, all Section 16(a) filing requirements during that fiscal year were met.

The following table sets forth information for our executive officers as of the date of this Proxy Statement:

Biographical information for Marc H. Hedrick, M.D. is included above with the director biographies in the section titled “Biographical Information About Our Director Nominees.”

Andrew Sims. Mr. Sims joined us as Chief Financial Officer in February 2020. Prior to his appointment as our Chief Financial Officer, Mr. Sims held roles at several private equity-backed companies. Between 2012 and 2017, Mr. Sims was Chief Financial Officer of Amplify LLC, an advisory and management consulting services firm. Following his time at Amplify, Mr. Sims served as Chief Financial Officer of Verbatim Support Services LLC, a litigation support company, from 2017 to 2019. His focus has been on mergers and acquisitions, integrations, corporate capitalization and building out and managing teams to support global growth. Previously, Mr. Sims was Partner at Mazars, a global accounting, advisory, audit, tax and consulting firm. Working from both the Oxford, England and New York offices, Mr. Sims audited and advised global public clients, including a variety of healthcare companies, with average annual revenues in excess of $1 billion. Further, he was the lead partner on over fifty (50) acquisitions ranging from $5 million to $4 billion in purchase price. He is a Certified Public Accountant in the U.S. and a Chartered Accountant in England and Wales. Mr. Sims is a graduate of Buckingham University in the United Kingdom.

The following table provides information for the compensation awarded to or earned by our Chief Executive Officer and our two other most highly compensated executive officers for fiscal years 2024 and 2023, or collectively, the named executive officers (the “NEOs”):

On May 13, 2020 we entered into Amended and Restated Executive Employment Agreements with each of Dr. Hedrick (the “Hedrick Employment Agreement”) and Mr. Sims (the “Sims Employment Agreement” and, together with the Hedrick Employment Agreement, the “Executive Employment Agreements”). The Executive Employment Agreements generally provide for a minimum base salary, a discretionary annual cash bonus based on the achievement of Company performance goals and the ability to participate in, subject to applicable eligibility requirements, all of our benefit plans and fringe benefits and programs that may be provided to our executives from time to time. Dr. Hedrick is also eligible for certain severance payments as described further below under “Potential Payments upon Termination or Change-in-control” below.

The Compensation Committee operates in accordance with the compensation committee charter (the “Compensation Committee Charter”). The Compensation Committee Charter outlines responsibilities and duties of the members, sets forth the frequency of meetings, establishes and reviews the overall compensation policies and practices of the Company and also sets forth the process to review and approve the executive compensation program for the Chief Executive Officer and other executive officers, and makes appropriate recommendations to the Board.

The Compensation Committee approves or makes recommendations to our Board on decisions concerning compensation of the executive management team and the Board on a periodic basis to ensure that it is consistent with our short-term and long-term goals. The Compensation Committee assesses the appropriateness of the nature and amount of compensation of our executives by reference to relevant employment market conditions with the overall objective of ensuring maximum stakeholder benefit from the recruitment and retention of a high-quality board and executive team.

Additionally, the Compensation Committee is responsible for evaluating the performance of the Company’s key senior executives. The Company’s Chief Executive Officer and other members of management regularly discuss

the Company’s compensation issues with Compensation Committee members. The Compensation Committee reviews and recommends to the Board the overall bonus and equity incentive awards for employees of the Company. Additionally, the Company’s Chief Executive Officer makes recommendations to the Compensation Committee for review, modification (if applicable) and approval in relation to bonuses and equity incentive awards for members of the executive management team.

In the process of determining compensation for our NEOs, the Compensation Committee considers the current financial position of the Company, the strategic goals of the Company, and the performance of each of our NEOs. The Compensation Committee retained Anderson Pay Advisors in January 2023 and January 2024, to perform an independent compensation review and to provide compensation research, analysis and recommendations. In addition, from time to time, the Compensation Committee considers the various components (described below) of our executive compensation program in relation to compensation paid by other public companies, compensation data from Radford Global Life Sciences Survey, a historical review of all executive officer compensation, and recommendations from our Chief Executive Officer (other than for his own compensation). The Compensation Committee has the sole authority to select, compensate and terminate its external advisors.

The Compensation Committee utilizes the following components of compensation (described further below) to strike an appropriate balance between promoting sustainable and excellent performance and discouraging any excessive risk-taking behavior:

Our NEOs receive a base salary to compensate them for services rendered to us. The base salary payable to each named executive officer is intended to provide a fixed component of compensation reflecting the executive’s skill set, experience, role and responsibilities. None of the NEOs is currently party to an agreement or arrangement that provides for automatic or scheduled increases in base salary.

We designed our long-term equity grant program to further align the interests of our executives with those of our stockholders, provide our executives with a strong link to our long-term performance and create an ownership culture. Historically, the Compensation Committee has granted stock options, although from time-to-time, to further increase the emphasis on performance-based compensation, the Compensation Committee may grant other equity awards as allowed by the 2020 Stock Incentive Plan, based on its judgment as to whether the complete compensation packages given to our executives, including prior equity awards, are appropriate and sufficient to retain and incentivize the executives and whether the grants balance long-term versus short-term compensation. The Compensation Committee also considers our overall performance as well as the individual performance of each of our NEOs, the potential dilutive effect of restricted stock awards, the dilutive and overhang effect of the equity awards and recommendations from the Chief Executive Officer (other than with respect to his own equity awards).

Stock options are granted with an exercise price equal to the fair market value of our Common Stock on the date of grant.

For the year ended December 31, 2024, our Chief Executive Officer was awarded stock options covering a total of 291,607 shares, our Chief Financial Officer was awarded stock options covering a total of 65,007 shares and our former Chief Medical Officer was issued a stock option covering 24,073 shares. For the year ended December 31, 2023, our Chief Executive Officer was awarded stock options covering a total of 6,720 shares, our Chief Financial Officer was awarded stock options covering a total of 1,451 shares and our former Chief Medical Officer was issued a stock option covering 1,047 shares. You can find more information on the stock options granted to our Named Executive Officers below under “Outstanding Equity Awards at December 31, 2024” heading below.

Target bonuses are reviewed annually and established as a percentage of the NEOs’ base salaries, generally based upon seniority of the officer and targeted at or near the median of the peer group and relevant survey data (including the Radford Global Life Sciences Survey). Each year, the Compensation Committee establishes corporate objectives related to the Company’s clinical, financial and operational goals and sets each NEO’s respective bonus target percentages, taking into account recommendations from our Chief Executive Officer as it relates to individual objectives for executive positions other than the Chief Executive Officer. Our Chief Executive Officer’s target bonus is set by the Compensation Committee to align entirely with our overall corporate objectives. Our other NEOs have additional individual goals, the attainment of which comprises a specified percentage of their total bonus compensation. After each fiscal year-end, our Chief Executive Officer provides the Compensation Committee with a written evaluation showing actual performance as compared to corporate and/or individual objectives, and the Compensation Committee uses that information, along with the overall corporate performance, to determine what percentage of each executive’s bonus target will be paid out as a bonus for that year. Overall, the Compensation Committee seeks to establish corporate and individual functional goals to be challenging, yet attainable, and stretch goals to be highly challenging.

Dr. Hedrick’s target bonus for the Company’s 2024 and 2023 fiscal years, as a percentage of base salary, was fifty-five percent (55%). Mr. Sims’ target bonus as a percentage of base salary was forty percent (40%) and thirty-five percent (35%) for the Company’s 2024 and 2023 fiscal years, respectively, and Dr. LaFrance’s target bonus for the Company’s 2024 and 2023 fiscal years, as a percentage of base salary, was thirty-five percent (35%).

For the Company’s 2024 fiscal year, the corporate goals approved by the Board (upon recommendation of the Compensation Committee for purposes of executive compensation) were determined by the Compensation Committee to have been achieved at a level of 105%. As our Chief Executive Officer’s bonus is based exclusively on attainment of our corporate goals, Dr. Hedrick received $321,321, or 105% of his target cash bonus. Based upon the attainment of 105% of the corporate goals, and upon an attainment of 105% of his individual goals, our Chief Financial Officer, Mr. Sims, received $156,555, or 105% of his target cash bonus. Dr. LaFrance left his position of Chief Financial Officer on June 11, 2024 and was not eligible for a bonus in 2024.

For the Company’s 2023 fiscal year, the corporate goals approved by the Board (upon recommendation of the Compensation Committee for purposes of executive compensation) were determined by the Compensation Committee to have been achieved at a level of 110%. As our Chief Executive Officer’s bonus is based exclusively on attainment of our corporate goals, Dr. Hedrick received $336,622, or 110% of his target cash bonus. Based upon the attainment of 110% of the corporate goals, and (i) upon an attainment of seventy-five percent (75%) of his individual goals, our Chief Financial Officer, Mr. Sims, received $125,803, or 101% of his target cash bonus; and (ii) upon an attainment of 100% of his individual goals, our former Chief Medical Officer, Dr. LaFrance, received $161,700, or 105% of his target cash bonus.

All of our executives are eligible to participate in our employee benefit plans, including medical, dental, vision, life insurance, short-term and long-term disability insurance, flexible spending accounts and 401(k). These plans are available to all full-time employees. In keeping with our philosophy to provide total compensation that is competitive within our industry, we offer limited personal benefits and perquisites to executive officers. You can find more information on the amounts paid for these perquisites to, or on behalf of, our NEOs in our Summary Compensation Table.

The following table sets forth certain information regarding equity awards granted to our NEOs that remain outstanding as of December 31, 2024.

Pursuant to the terms of the Executive Employment Agreements, if one of our NEOs is terminated without “cause” or resigns for “good reason,” (both, a “Severance Termination”), then such NEO will be eligible to receive: (i) an amount equal to twelve (12) months of his base salary; (ii) an amount equal to his target bonus for the year in which such Severance Termination occurs; (iii) the annual bonus earned for the prior calendar year, if not yet paid, as of the date of such Severance Termination; (iv) an amount equal to twelve (12) months of the premiums such NEO is required to pay under the Consolidated Omnibus Budget Reconciliation Act of 1985, as amended (“COBRA”), to continue coverage for him and his eligible dependents under our group health plans; and (v) the accelerated vesting of such NEO’s unvested equity incentive awards that would have vested during the period beginning on the date of such Severance Termination and ending on (a) in case of a Severance Termination of Dr. Hedrick, twelve (12) months thereafter, or (b) in the case of a Severance Termination of Mr. Sims, nine (9) months thereafter. In order to be eligible for the benefits set forth above, such NEO must sign (and not revoke) a general release of claims in favor of the Company as of the date of the Severance Termination, as applicable (a “Release”).

If a Severance Termination occurs within the period beginning on the date the Company and an acquiror formally or informally agree on the terms of a transaction which, if consummated, would constitute a “change in control” and ending on the closing date of the change in control, or within twelve (12) months following a change in control, upon signing a Release (a “CoC Termination”), such NEO will be eligible to receive: (i) those items listed in the above

paragraph under subclauses (ii) and (iii); (ii) an amount equal to (a) in the case of a CoC Termination of Dr. Hedrick, eighteen (18) months of the greater of his base salary in effect immediately prior to the date of such CoC Termination and his base salary in effect on the date the terms of a transaction that results in a change in control are agreed to, or (b) in the case of a CoC Termination of Mr. Sims, twelve (12) months of the greater of his base salary in effect immediately prior to the date of such CoC Termination and his base salary in effect on the date the terms of a transaction that results in a change in control are agreed to; (iii) the amounts listed in the above paragraph under subclause (iv), except that, if the CoC Termination is for Dr. Hedrick, the amount of the COBRA payment will be increased to eighteen (18) months; (iv) the acceleration of such NEO’s remaining unvested equity incentive awards effective on the later of the CoC Termination and the date of the change in control; and (v) the right to exercise the equity incentive awards granted to him on or after the date of his Executive Employment Agreement until the later of (a) three (3) months after the CoC Termination, (b) three (3) months following the change in control with respect to any equity incentive awards that become exercisable upon a change in control due to the acceleration in connection with the change in control and (c) any period specified in such NEO’s award agreements (but not beyond the original expiration date of any equity incentive award). Further, even if a CoC Termination does not occur, if any of our NEOs remain employed by the Company as of the closing of such change in control, all of such NEO’s outstanding unvested incentive stock awards shall automatically accelerate on the date of such change of control.

Under the Executive Employment Agreements, the term “cause” generally refers to the occurrence of certain events including (i) the employee’s extended disability, (ii) the employee’s repudiation of his employment or his Executive Employment Agreement, (c) the employee’s conviction of a felony or certain misdemeanors, (iv) the employee’s demonstrable and documented fraud, (v) an intentional, reckless or grossly negligent action which causes material harm to the Company, (vi) an intentional failure to substantially perform material employment duties or directives, and (vii) the chronic absence from work for reasons other than illness, permitted vacation or resignation for good reason.

Under the Executive Employment Agreements, the term “good reason” generally refers to: (i) the Company’s material breach of its obligation to pay the employee the compensation earned for any past service (at the rate which had been stated to be in effect for such period of service); (ii) a change in the employee’s position with the Company which materially reduces the employee’s duties or stature in the business conducted by the Company; and (iii) a reduction in the employee’s level of compensation, provided, however, that a Company-wide reduction of compensation of not more than fifteen percent (15%) that is also applicable to all of the senior management of the Company and which continues for less than three (3) months, shall not constitute good reason.

Under the Executive Employment Agreements, the term “change of control” generally refers to (i) a change in the composition of the Board, as a result of which fewer than one-half (1/2) of the incumbent directors are directors who either: (a) had previously been directors of the Company; or (b) were elected, or were nominated for election, to the Board with the affirmative votes of at least a majority of the aggregate of the original directors who were still in office at the time of the election or nomination and the directors whose election or nomination was previously so approved; (ii) any “person” who, by the acquisition or aggregation of securities, is or becomes the “beneficial owner” (as defined in Rule 13d-3 under the Exchange Act), directly or indirectly, of securities of the Company representing fifty percent (50%) or more of the combined voting power of the Company’s then outstanding securities ordinarily having the right to vote at elections of directors (the “Base Capital Stock”); except that any change in the relative beneficial ownership of the Company’s securities, by any person, resulting solely from a reduction in the aggregate number of outstanding shares of Base Capital Stock, and any decrease thereafter in such person’s ownership of securities, shall be disregarded until such person increases, in any manner, directly or indirectly, such person’s beneficial ownership of any securities of the Company; (iii) the consummation of a merger or consolidation of the Company with or into another entity or any other corporate reorganization, if persons who were not stockholders of the Company immediately prior to such merger, consolidation or other reorganization own, immediately after such merger, consolidation or other reorganization, fifty percent (50%) or more of the voting power of the outstanding securities of each of (a) the continuing or surviving entity and (b) any direct or indirect parent corporation of such continuing or surviving entity; or (iv) the sale, transfer or other disposition of all or substantially all of the Company’s assets.

The Company does not have any agreements or plans, other than the Executive Employment Agreements, in place for the NEOs that would provide additional compensation in connection with a retirement, termination for cause or resignation without good reason.

Our Board believes that the level of director compensation should be based on time spent carrying out Board and committee responsibilities and be competitive with comparable companies. In addition, the Board believes that a significant portion of director compensation should align director interests with the long-term interests of stockholders. The Board makes changes in its director compensation practices upon the recommendation of the Compensation Committee and following discussion and approval by the Board.

Our Board, following the Compensation Committee’s recommendation, approved the 2024 compensation of our non-employee directors, as described below. The compensation level of our non-employee directors is expected to remain the same in 2025.

On February 22, 2024, each non-employee director was awarded a grant of options for 2,250 shares as equity compensation and on September 11, 2024 awarded a grant of options for 3,650 shares as equity compensation.

The following table summarizes director compensation awarded to, earned by or paid to our non-employee directors who served on our Board during fiscal year 2024:

In accordance with Item 402(v) of Regulation S-K, we are providing the following descriptions of the relationships between information presented in the Pay Versus Performance table on CAP and each of total shareholder return (“TSR”) and net loss.

We do not utilize TSR and net loss in our executive compensation program. However, we do utilize several other performance measures to align executive compensation with our performance. As described in more detail above in the section “Annual Bonuses and Non-Equity Incentive Plan Compensation,” part of the compensation our NEOs are eligible to receive consists of annual performance-based cash bonuses that are designed to provide our executives appropriate incentives to achieve defined annual corporate goals and to reward our executives for individual achievement towards these goals, subject to certain employment criteria. Additionally, we view stock options, which are an integral part of our executive compensation program, as related to company performance although not directly tied to TSR, because they provide value only if the market price of our Common Stock increases, and if the executive officer continues in our employment over the vesting period. These stock option awards strongly align our executive officers’ interests with those of our stockholders by providing a continuing financial incentive to maximize long-term value for our stockholders and by encouraging our executive officers to continue in our employment for the long-term.

With respect to net income, specifically, because we are not a commercial-stage company, we did not have any revenue during the periods presented, other than revenue associated with grants. Consequently, our company does not consider net loss as a performance measure for our executive compensation program. In 2023, our net loss increased from 2022, which was primarily due to increases in research and development expenses and costs associated with the settlement of litigation.

 

The graphs below compare the compensation actually paid to our Chief Executive Officer and the average of the compensation actually paid to our remaining NEOs, with (i) our cumulative TSR, and (ii) our net income, in each case, for the fiscal years ended December 31, 2022, 2023 and 2024. TSR amounts reported in the graph assume an initial fixed investment of $100.

 

The following table gives information, as of December 31, 2024, about shares of our Common Stock that may be issued upon the exercise of outstanding options, and shares remaining available for issuance under all of our equity compensation plans:

The following table sets forth information regarding the beneficial ownership of our Common Stock as of June 18, 2025, by (i) each person, or group of affiliated persons, known to us to beneficially own more than five percent (5%) of the outstanding shares of our Common Stock, (ii) each of our directors, (iii) each of our named executive officers and (iv) all current directors and named executive officers as a group.

Information with respect to beneficial ownership is based on information furnished to us by each director or executive officer. Information about our 5% or greater stockholder, other than percentages of beneficial ownership, is based solely on Schedules 13G or 13D filed with the SEC. Beneficial ownership is determined according to the rules of the SEC and generally means that a person has beneficial ownership of a security if she, he or it possesses sole or shared voting or investment power of that security and includes options and warrants that are currently exercisable within 60 days of June 18, 2025. Options to purchase shares of our Common Stock that are exercisable within 60 days of June 18, 2025, are deemed to be beneficially owned by the persons holding these options for the purpose of computing percentage ownership of that person but are not treated as outstanding for the purpose of computing any other person’s ownership percentage. Except as indicated in the footnotes below, each of the beneficial owners named in the table below has, to our knowledge, sole voting and investment power with respect to all shares of Common Stock listed as beneficially owned by her, him or it, except for shares owned jointly with that person’s spouse or as may otherwise be set forth in a footnote.

We have based our calculation of beneficial ownership on 60,490,101 shares of our Common Stock outstanding as of June 18, 2025. Unless otherwise indicated, the address for each of the stockholders in the table below is c/o Plus Therapeutics, Inc., 2710 Reed Road, Suite 160, Houston, TX 77002.

We adopted the 2015 Plan on December 29, 2015 pursuant to Rule 5653(c)(4) of the Nasdaq. The 2015 Plan was subsequently amended by the Board in May 2016, January 2020 and June 2024.

Awards granted under the 2015 Plan were intended to constitute “employment inducement awards” under Nasdaq Listing Rule 5635(c)(4) and, therefore, the 2015 Plan was intended to be exempt from the Nasdaq Listing Rules regarding stockholder approval of stock option and stock purchase plans. The 2015 Plan provides for the grant of restricted stock unit awards, restricted stock awards, performance awards, unrestricted securities, stock-equivalent units, stock appreciation units, securities or debentures convertible into Common Stock or other forms. These awards may be granted to individuals who were then new employees, or were commencing employment with us or with one of our subsidiaries following a bona fide period of non-employment with us, and for whom such awards were granted as a material inducement to commencing employment with us or one of our subsidiaries.

The 2015 Plan is administered by the Compensation Committee. The plan administrator has discretion to take action under the 2015 Plan, such as determining the purchase price, performance measures and any repurchase rights, as well as make adjustment to the terms of any Award to reflect, or related to, such changes in our capital structure or distributions as we deem appropriate, including modification of performance goals, performance award formulas and performance periods. As of June 18, 2025, there were 76,025 shares of Common Stock remaining and available for issuance under the 2015 Plan.

On June 16, 2020, our stockholders approved the Plus Therapeutics, Inc. 2020 Stock Incentive Plan (the “2020 Plan”), which replaced the Company’s 2014 Equity Incentive Plan. The 2020 Plan, as amended, provides for the issuance of up to 3,550,000 shares of Common Stock, plus the number of shares available for issuance is increased to the extent that awards granted under the 2020 Plan and the 2014 Equity Incentive Plan are forfeited or expire (except as otherwise provided in the 2020 Plan). As of June 18, 2025, there were 47,409 shares available for future grant under the 2020 Plan.

The 2020 Plan provides for the direct award or sale of shares of Common Stock (including restricted stock), the award of stock units and stock appreciation rights and the grant of both incentive stock options to purchase Common Stock intended to qualify for preferential tax treatment under Section 422 of the U.S. Code (the “Code”) and nonstatutory stock options to purchase Common Stock that do not qualify for such treatment under the Code. All employees (including officers) and directors of the Company or any subsidiary and any consultant

who performs services for us or a subsidiary are eligible to purchase shares of Common Stock and to receive awards of shares or grants of nonstatutory stock options, stock units and stock appreciation rights. Only employees are eligible to receive grants of incentive stock options.

The 2020 Plan is administered by the Compensation Committee. Subject to the limitations set forth in the 2020 Plan, the Compensation Committee has the authority to determine, among other things, to whom awards will be granted, the number of shares subject to awards, the term during which an option, stock unit or stock appreciation right may be exercised and the rate at which the awards may vest or be earned, including any performance criteria to which they may be subject. The Compensation Committee also has the authority to determine the consideration and methodology of payment for awards.

The additional information required by this item will be set forth under the caption “Security Ownership of Certain Beneficial Owners and Management” and “Executive Compensation—Equity Compensation Plan Information” in the Proxy Statement and is incorporated herein by reference.

The Board has unanimously determined that Mr. Clowes, Dr. van Es-Johansson, Mr. Hawkins, Dr. Lenk and Mr. Guse are “independent” under the applicable standards of Nasdaq and the SEC.

Dr. Hedrick has served as the Company’s President and Chief Executive Officer since 2004 and 2014, respectively, and therefore is not an independent director.

All of the directors who serve as members of the Audit Committee, the Compensation Committee and the Nominating and Corporate Governance Committee are independent under our independence standards, Nasdaq listing standards and the applicable rules of the SEC.

We have adopted a written Related Person Transactions Policy that sets forth our policies and procedures regarding the identification, review, consideration and oversight of “related person transactions.” For purposes of our policy only, a “related person transaction” includes, subject to certain exceptions, a transaction, arrangement or relationship (or any series of similar transactions, arrangements or relationships) in which we or our subsidiary participate involving an amount that exceeds $120,000, in which any “related person” has a material interest.

Transactions involving compensation for services provided to us as an employee, consultant or director are not considered related person transactions under this policy. A related person is any executive officer, director, nominee to become a director or a holder of more than five percent (5%) of any class of our voting securities (including our Common Stock), including any of their immediate family members and affiliates, including entities owned or controlled by such persons.

The policy is administered by the Audit Committee, which will approve only those transactions that are, in its judgment, appropriate or desirable under the circumstances. Under the policy, the related person in question or, in the case of transactions with a holder of more than five percent (5%) of any class of our voting securities, an officer with knowledge of the proposed transaction, must present information regarding the proposed related person transaction to our Audit Committee (or, where review by our Audit Committee would be inappropriate, to another independent body of our Board) for review. To identify related person transactions in advance, we rely on information supplied by our executive officers, directors, and certain significant stockholders. In considering related person transactions, our Audit Committee considers the relevant available facts and circumstances, which may include among other factors:

Whether the transaction would present an improper conflict of interest for any director, director nominee or executive officer, is determined by taking into account the size of the transaction, the overall financial position of the applicable related person, the direct or indirect nature of the applicable related person, the ongoing nature of any proposed relationship and any other relevant factors.

No director may participate in the discussion or approval of a transaction in which that director, or an immediate family member of that director, has a direct or indirect interest.

Our Audit Committee will approve only those transactions that it determines are fair to us and in our best interests.

The following includes a summary of any related party transactions during the last two completed fiscal years to which we have been a party. We also describe below certain other transactions with our directors, executive

officers and 5% stockholders. We believe the terms obtained or consideration that we paid or received, as applicable, in connection with the transactions described below were comparable to terms available or the amounts that would be paid or received, as applicable, from unaffiliated third parties.

In May 2024, the Company entered into a securities purchase agreement (the “Securities Purchase Agreement”) with certain investors (the “Purchasers”), including certain of the Company’s directors and executive officers (“Company Insiders”), for the sale and issuance by the Company of its securities (the “Initial Subscription”). On May 8, 2024, the Company entered into a first amendment to the Securities Purchase Agreement (the “Amendment”, and together with the Securities Purchase Agreement, the “Purchase Agreement”) for the sale and issuance by the Company of additional securities to two of the Purchasers (the “Additional Subscription”, and together with the Initial Subscription, the “May 2024 PIPE Financing”). The Purchase Agreement provides for the sale and issuance by the Company of an aggregate of 3,591,532 shares (the “Private Placement Shares”) of the Company’s Common Stock or, at the election of each purchaser, pre-funded warrants (the “Pre-Funded Warrants”), exercisable immediately at an exercise price of $0.001 per share (the “Pre-Funded Warrant Shares”), with each Private Placement Share or Pre-Funded Warrant accompanied by (i) a Series A common warrant (“Series A Warrants”) to purchase one share of Common Stock (the “Series A Warrant Shares”), for an aggregate of 3,591,532 Series A Warrants, and (ii) one Series B common warrant (“Series B Warrants”) to purchase one share of Common Stock (the “Series B Warrant Shares,” and together with the Series A Warrant Shares, the “Common Warrant Shares”), for an aggregate of 3,591,532 Series B Warrants.

The combined purchase price for each Private Placement Share and Pre-Funded Warrant from the Initial Subscription was $2.022, and $2.158 for the accompanying Series A Warrant and one accompanying Series B Warrant, provided, that the Company Insiders participated in the Initial Subscription at an offering price of $2.04 per Private Placement Share and accompanying Series A Warrant and Series B Warrant. The exercise price of each Series A Warrant and Series B Warrant from the Initial Subscription is $1.772 per share and $1.908 per share in the Additional Subscription, provided that the exercise price for the Series A Warrants and Series B Warrants issued to the Company Insiders is $1.79 per share. Subject to certain ownership limitations, the Series A Warrants are exercisable until the five-year anniversary of issuance. Subject to certain ownership limitations, the Series B Warrants were exercisable until June 24, 2025. The Pre-Funded Warrants will not expire until exercised in full.

The aggregate gross proceeds at the May 2024 PIPE Financing closing were approximately $7.25 million, before deducting certain expenses payable by the Company, and excluding the proceeds, if any, from the exercise of the Series A Warrants, the Series B Warrants and Pre-Funded Warrants (collectively, the “Warrants”).

The following table sets forth the aggregate number of Private Placement Shares and Warrants purchased by the Company Insiders in the May 2024 PIPE Financing:

Also in May 2024, we entered into a registration rights agreement (“Registration Rights Agreement”) with the Purchasers. Pursuant to the Registration Rights Agreement, we agreed to register for resale the shares of common stock issued pursuant to the Purchase Agreement and the Common Stock underlying the Warrants (the “Registrable Securities”). Under the Registration Rights Agreement, we agreed to file a registration statement covering the resale of the Registrable Securities no later than 30 days following the closing of the May 2024 PIPE Financing. We filed with the SEC a registration statement on Form S-1 covering the resale of the Registrable Securities on June 7, 2024 (File No.: 333-280061), which was declared effective by the SEC on June 24, 2024.

Our Certificate of Incorporation and Bylaws provide that we will indemnify each of our directors and officers to the fullest extent permitted by the Delaware General Corporation Law.

We have entered into employment agreements with our executive officers pursuant to which we pay our executive officers annual salaries and bonuses as more fully described above under “Executive Compensation.” Further, we have granted stock options to our executive officers and non-employee directors as more fully described above under “Director Compensation.”

The following table summarizes the aggregate fees for professional services billed to us by BDO USA, P.C. and their respective affiliates (collectively, “BDO”) for the periods set forth below:

Our Audit Committee Charter, which is available on our website at https://ir.plustherapeutics.com/governance/board-committees, requires the Audit Committee to pre-approve all audit and non-audit services to be provided by our independent registered public accounting firm in accordance with the charter of the Audit Committee. All services reported in the audit, audit-related fees and tax fees categories above were approved by the Audit Committee.

The following report of the Audit Committee does not constitute soliciting material and shall not be deemed filed or incorporated by reference into any other filing by Plus Therapeutics, Inc. under the Securities Act of 1933, as amended, or the Exchange Act, whether made before or after the date hereof and irrespective of any general incorporation language in any such filing.

The Audit Committee is a committee of the Board comprised solely of independent directors as required by the listing standards of Nasdaq and the rules and regulations of the SEC. The Audit Committee provides assistance to the Board in fulfilling its legal and fiduciary obligations in matters involving the Company’s accounting, auditing, financial reporting, internal control and legal compliance functions by approving the services performed by BDO USA, P.C. and reviewing their reports regarding the Company’s accounting practices and systems of internal accounting controls as set forth in a written charter adopted by the Board, which is available on the Company’s website at https://plustherapeutics.com/. The composition and responsibilities of the Audit Committee, as reflected in its charter, are intended to be in accordance with applicable requirements. The Audit Committee reviews and assesses the adequacy of its charter and the Audit Committee’s performance on an annual basis.

The Company’s management is responsible for preparing the Company’s financial statements and the independent registered public accountants are responsible for auditing those financial statements. The Audit Committee is responsible for overseeing the conduct of these activities by the Company’s management and the independent registered public accountants. In this context, the Audit Committee has met and held discussions with management and the independent registered public accountants.

Management represented to the Audit Committee that the Company’s consolidated financial statements were prepared in accordance with U.S. generally accepted accounting principles, and the Audit Committee has reviewed and discussed the consolidated financial statements with management and the independent registered public accountants.

The Audit Committee has discussed with the independent registered public accountants matters required to be discussed by Auditing Standard No. 1301, as adopted by the Public Company Accounting Oversight Board (“PCAOB”) and approved by the SEC. In addition, the independent registered public accountants provided to the Audit Committee the written disclosures and letter from such accountants as required by applicable requirements of the PCAOB regarding such accountants’ communications with the Audit Committee concerning

independence and the Audit Committee has discussed with such accountants such accountants’ independence from the Company and its management. The Audit Committee has discussed with management and the independent registered public accountants the procedures for selection of consultants, fully considered whether those services provided by the independent registered public accountants are compatible with maintaining such accountants’ independence and has determined that the non-audit services performed by such accountants are compatible with maintaining their independence.

The Audit Committee has discussed with the Company’s management and its independent registered public accountants, with and without management present, their evaluations of the Company’s internal accounting controls and the overall quality of the Company’s financial reporting. In reliance on the reviews and discussions with management and the independent registered public accountants referred to above, the Audit Committee recommended to the Board, and the Board has approved, the inclusion of the audited financial statements in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2024, and filed with the SEC.

Respectfully submitted,

Kyle Guse, Chairman

Howard Clowes

An van Es-Johansson, M.D.

The Board, upon the recommendation of our Nominating and Corporate Governance Committee, has nominated Howard Clowes, An van Es-Johansson, M.D., Richard J. Hawkins, Marc H. Hedrick, M.D., Robert Lenk, Ph.D., and Kyle Guse as director nominees for election at the Annual Meeting.

Our Board is currently comprised of six directors. As described in our Bylaws, all director nominees will stand for election for one-year terms that expire at the following year’s annual meeting, unless they resign, are removed or their respective successors are duly elected and qualified. If any nominee should decline or be unable to accept such nomination to serve as a director, or for good cause will not serve as a director—an event which our Board does not currently anticipate—our Board reserves the right to nominate another person or to vote to reduce the size of our Board. The designated proxy holders will have the express discretionary authority to vote for a replacement nominee and proxies will be voted for any nominee designated by our Board to fill the vacancy. If another person is nominated, the proxy holders intend to vote the shares to which the proxy relates for the election of the persons nominated by our Board.

Biographical information and the attributes, skills and experience of each nominee that led our Nominating and Corporate Governance Committee and Board to determine that such nominee should serve as a director are discussed in the “Biographical Information About Our Director Nominees” and “Criteria for Board Membership” sections, respectively, of this Proxy Statement and is incorporated into this section by reference.

The nominees will be elected by a plurality vote, which means that the six (6) director nominees receiving the highest number of “FOR” votes will be elected. Only votes “FOR” will affect the outcome. Broker non-votes will have no effect.

YOUR BOARD UNANIMOUSLY RECOMMENDS A VOTE “FOR” THE NOMINEES TO THE BOARD NAMED ABOVE.

On June 17, 2025, we entered into the Lincoln Park Purchase Agreement with Lincoln Park Capital Fund, LLC (“Lincoln Park”) and a related registration rights agreement (the “Registration Rights Agreement”). Pursuant to the Lincoln Park Purchase Agreement, Lincoln Park has agreed to purchase from us up to an aggregate of $50.0 million of shares our Common Stock. We are submitting this proposal to our stockholders in order to obtain the requisite stockholder authorization in accordance with Nasdaq listing rules, specifically Rule 5635(d), to issue and sell shares of our Common Stock to Lincoln Park in excess of 19.99% of the outstanding shares of our Common Stock as of the date we entered into the Lincoln Park Purchase Agreement. Nothing contained in the Lincoln Park Purchase Agreement obligates us to issue and sell any shares, other than the Commitment Shares (as defined below), and any sales by us under the Lincoln Park Purchase Agreement would be made at our sole election and in our discretion, subject to the terms and satisfaction of the conditions contained in the Lincoln Park Purchase Agreement.

The affirmative vote of a majority of the Common Stock having voting power present at the Annual Meeting or represented by proxy at the Annual Meeting is required to approve this proposal. Abstentions will be counted as present for purposes of determining a quorum and are considered shares present and entitled to vote and thus will have the effect of a vote “AGAINST” this proposal.

OUR BOARD UNANIMOUSLY RECOMMENDS THAT THE STOCKHOLDERS VOTE “FOR” THE APPROVAL OF THE POTENTIAL ISSUANCE OF (I) UP TO $50 MILLION OF OUR ISSUED AND OUTSTANDING COMMON STOCK AND (II) UP TO $1 MILLION OF COMMITMENT SHARES, PURSUANT TO THE LINCOLN PARK PURCHASE AGREEMENT.

Under the terms and subject to the conditions of the Lincoln Park Purchase Agreement, we have the right, but not the obligation, to sell to Lincoln Park, and Lincoln Park is obligated to purchase, up to $50.0 million of shares of Common Stock. Such sales of Common Stock by us, if any, are subject to certain limitations, and may occur from time to time, at our sole discretion, over the 36-month period (the “Commitment Period”) commencing after the satisfaction of certain conditions set forth in the Lincoln Park Purchase Agreement, including the effectiveness of a registration statement that we filed with the SEC in accordance with the terms of the Registration Rights Agreement, pursuant to which we have registered for resale by Lincoln Park 17,000,000 shares of Common Stock that we may issue and sell under the Lincoln Park Purchase Agreement. The Commitment Period began on June 23, 2025.

Under the Lincoln Park Purchase Agreement, for a period of up to 36-months following the date on which all applicable conditions have been satisfied, on any business day that we select on which the closing sale price of our common stock equals or exceeds $0.10 per share, we may direct Lincoln Park to purchase up to 300,000 shares of our Common Stock in a “Regular Purchase” on such business day; provided, however, that (i) the Regular Purchase may be increased to up to 400,000 shares of our Common Stock if the closing sale price of our Common Stock is not below $0.50 on the purchase date, and (ii) the Regular Purchase may be increased to up to 500,000 shares of our Common Stock if the closing sale price of our Common Stock is not below $0.75 on the purchase date (such share amount limitation, the “Regular Purchase Share Limit”). In each case, Lincoln Park’s maximum commitment in any single Regular Purchase may not exceed $1,000,000. The Regular Purchase Share Limit is generally subject to proportionate adjustment for any reorganization, recapitalization, non-cash dividend, stock split, reverse stock split or other similar transaction as provided in the Lincoln Park Purchase Agreement.

The purchase price per share for each such Regular Purchase will be equal to the 97% of the lower of: (i) the lowest sale price for our Common Stock on the purchase date for such Regular Purchase; and (ii) the arithmetic average of the three lowest closing sale prices for our Common Stock during the 10 consecutive business days ending on the business day immediately preceding the purchase date for such Regular Purchase.

In addition to Regular Purchases described above, on any purchase date for a Regular Purchase on which we have properly submitted a Regular Purchase notice directing Lincoln Park to purchase the maximum number of shares of our Common Stock that we are then permitted to include in a single Regular Purchase notice (and provided all shares of Common Stock subject to all prior Regular Purchases, Accelerated Purchases (as defined below) and Additional Accelerated Purchases (as defined below) that we have effected under the Lincoln Park Purchase Agreement prior to such purchase date, if any, have been received by Lincoln Park before we deliver notice to Lincoln Park for such Accelerated Purchase in accordance with the Lincoln Park Purchase Agreement), we may, by written notice delivered by us to Lincoln Park simultaneously with such Regular Purchase notice for such corresponding Regular Purchase, direct Lincoln Park to purchase an additional amount of our Common Stock, which we refer to as an “Accelerated Purchase,” on the next business day following such purchase date for such corresponding Regular Purchase, which we refer to as the “Accelerated Purchase Date,” not to exceed the lesser of: (i) 30% of the aggregate number of shares of our Common Stock traded during all or, if certain trading volume or market price thresholds specified in the Lincoln Park Purchase Agreement are crossed on the applicable Accelerated Purchase Date, the portion of the normal trading hours the applicable Accelerated Purchase Date prior to such time that any one of such thresholds is crossed, which period of time on the applicable Accelerated Purchase Date we refer to as the “Accelerated Purchase Measurement Period”; and (ii) 300% of the number of shares of Common Stock purchased pursuant to the corresponding Regular Purchase.

The purchase price per share for the shares of Common Stock subject to an Accelerated Purchase will be equal to 96.5% of the lower of: (i) the volume weighted average price of our Common Stock during the Accelerated Purchase Measurement Period on the applicable Accelerated Purchase Date; and (ii) the closing sale price of our Common Stock on the applicable Accelerated Purchase Date.

We may also direct Lincoln Park, by written notice delivered to Lincoln Park not later than 1:00 p.m., Eastern time, on an Accelerated Purchase Date (and provided all shares of Common Stock subject to all prior Regular Purchases, Accelerated Purchases and Additional Accelerated Purchases that we have effected under the Lincoln Park Purchase Agreement, including those prior Accelerated Purchases and Additional Accelerated Purchases effected on the same Accelerated Purchase Date as the applicable Additional Accelerated Purchase, if any, have been received by Lincoln Park in accordance with the Lincoln Park Purchase Agreement before we deliver notice to Lincoln Park for such Additional Accelerated Purchase), to purchase an additional amount of our Common Stock on such same Accelerated Purchase Date, which we refer to as an “Additional Accelerated Purchase,” of up to the lesser of: (i) 96.5% of the aggregate number of shares of our Common Stock traded during the portion of the normal trading hours on the applicable Accelerated Purchase Date determined in accordance with the Lincoln Park Purchase Agreement, which period of time on the applicable Accelerated Purchase Date we refer to as the Additional Accelerated Purchase Measurement Period; and (ii) three times the number of purchase shares purchased pursuant to the Regular Purchase corresponding to the Accelerated Purchase that was completed on such Accelerated Purchase date on which an Additional Accelerated Purchase notice was properly received.

The purchase price per share for the shares subject to an Additional Accelerated Purchase will be equal to 96.5% of the lower of: (i) the volume weighted average price of our Common Stock during the applicable Additional Accelerated Purchase Measurement Period for such Additional Accelerated Purchase; and (ii) the closing sale price of our Common Stock on the applicable same Accelerated Purchase Date.

As consideration for Lincoln Park’s commitment to purchase shares of the Company’s Common Stock upon the terms of and subject to satisfaction of the conditions set forth in the Purchase Agreement, the Company agreed to pay Lincoln Park an initial commitment fee on a date selected by the Company between July 1, 2025 and August 8, 2025 at a value of $500,000 in cash, shares of Common Stock or any combination thereof. An additional commitment fee of $500,000 will be paid if and when the Company sells over $25.0 million of the Company’s Common Stock under the Purchase Agreement. The additional commitment fee may be paid in cash, Common Stock, or any combination of cash and Common Stock.

In all instances, we may not sell shares of our Common Stock to Lincoln Park under the Lincoln Park Purchase Agreement if it would result in Lincoln Park beneficially owning more than 4.99% of our Common Stock. There are no upper limits on the price per share that Lincoln Park must pay for shares of Common Stock.

We currently intend to use the net proceeds from the sale of Common Stock to Lincoln Park for general corporate purposes.

As a result of the listing of our Common Stock on The Nasdaq Capital Market, issuances of our Common Stock are subject to the Nasdaq Listing Rules, including Rule 5635(d), which requires us to obtain stockholder approval prior to the issuance of securities in connection with a transaction, other than a public offering, involving the sale, issuance or potential issuance by us of more than 19.99% of our outstanding shares of our Common Stock (or securities convertible into or exercisable for shares of our Common Stock) at a price less than the lower of: (i) the closing price (as reflected on Nasdaq.com) immediately preceding the signing of the binding agreement; or (ii) the average closing price of the Common Stock (as reflected on Nasdaq.com) for the five trading days immediately preceding the signing of the binding agreement (the “Nasdaq 20% Rule”).

Under the Nasdaq 20% Rule, in no event may we issue or sell to Lincoln Park under the Lincoln Park Purchase Agreement more than 19.99% of the shares of our Common Stock outstanding immediately prior to the execution of the Lincoln Park Purchase Agreement (which was 10,194,593 shares, based on 50,998,468 of our shares outstanding immediately prior to the execution of the Lincoln Park Purchase Agreement) (the “Exchange Cap”), unless (i) the Company first obtains stockholder approval to issue shares of Common Stock in excess of the Exchange Cap in accordance with applicable Nasdaq listing rules, or (ii) at the time the Company has issued shares of Common Stock equal to the Exchange Cap and at all times thereafter, the average price per share of Common Stock for all shares of Common Stock sold by the Company to Lincoln Park under the Lincoln Park Purchase Agreement equals or exceeds $0.3576 per share (representing the sum of (i) $0.3086, representing the lower of (A) the official closing price of the Common Stock on Nasdaq on the trading day immediately preceding the date of the Lincoln Park Purchase Agreement and (B) the average official closing price of the Common Stock on Nasdaq for the five consecutive trading days ending on the trading day immediately preceding the date of the Lincoln Park Purchase Agreement, and (ii) $0.049, representing the adjustment amount under applicable Nasdaq rules to take into account the issuance of the Commitment Shares) (the “LP Minimum Price”), such that the Exchange Cap limitation would no longer apply to issuances and sales of Common Stock by the Company to Lincoln Park under the Lincoln Park Purchase Agreement under the Nasdaq 20% Rule. In any event, the Lincoln Park Purchase Agreement specifically provides that we may not issue or sell any shares of our Common Stock under the Lincoln Park Purchase Agreement if such issuance or sale would breach any applicable Nasdaq rules.

Based on the closing sale price of our Common Stock as reported on Nasdaq on [•], 2025, to fully utilize the $50 million amount available to us under the Lincoln Park Purchase Agreement, we would need to issue [•] shares of Common Stock to Lincoln Park, which would be in excess of the Nasdaq 20% Rule. Accordingly, in order to be able to sell to Lincoln Park the full amount available under the Lincoln Park Purchase Agreement at a price less than the LP Minimum Price, we are seeking stockholder approval to issue greater than 20% of our outstanding shares as of the date we entered into the agreement with Lincoln Park, which issuance would be effected under the Lincoln Park Purchase Agreement in accordance with its terms.

If the stockholders do not approve this proposal, then we will be unable to issue shares of Common Stock to Lincoln Park pursuant to the Lincoln Park Purchase Agreement in excess of the Exchange Cap if sold at a price less than the LP Minimum Price.

If we obtain stockholder approval as requested in this proposal, then we would no longer be subject to the Nasdaq 20% Rule restriction with respect to the issuance and sale of Common Stock to Lincoln Park under the Lincoln Park Purchase Agreement. If this proposal is approved by our stockholders, we would be able to issue more than the Exchange Cap (or 10,194,593 shares) to Lincoln Park under the Lincoln Park Purchase Agreement at a price less than the LP Minimum Price. The maximum number of shares of Common Stock that we may issue and sell to Lincoln Park under the Lincoln Park Purchase Agreement would fluctuate from time to time based on the price of our Common Stock. Assuming that our stockholders approve this proposal, and assuming and the total number of shares issuable under the Lincoln Park Purchase Agreement were issued on [•], 2025 at the closing price on that date, a total of [•] additional shares of Common Stock would be issuable to Lincoln Park, which have an approximate value of $50 million.

In addition, these additional shares of Common Stock that we could issue to Lincoln Park will result in greater dilution to existing stockholders and may result in a decline in our stock price or greater price volatility. Each

such additional share of Common Stock that would be issuable to Lincoln Park under the Lincoln Park Purchase Agreement would have the same rights and privileges as each share of our currently authorized Common Stock.

If a quorum is present, approval, for purposes of complying with Nasdaq Listing Rule 5635(d), of the potential issuance and sale of more than 20% of the Company’s issued and outstanding Common Stock pursuant to the Lincoln Park Purchase Agreement requires that a majority of the Common Stock having voting power present at the Annual Meeting or represented by proxy at the Annual Meeting are cast “FOR” approval. Abstentions will be counted as present for purposes of determining a quorum and are considered shares present and entitled to vote and thus will have the effect of a vote “AGAINST” this proposal.

YOUR BOARD UNANIMOUSLY RECOMMENDS A VOTE “FOR” THE APPROVAL OF THIS PROPOSAL.

On May 2, 2025, at a special meeting of stockholders (the “Special Meeting”), our stockholders voted in favor of authorizing our Board to effect a reverse stock split of all of our outstanding shares of Common Stock at a specific ratio within a range of one-for-twenty five (1-for-25) to a maximum of one-for-two hundred fifty (1-for-250), (the “May 2025 Approval”).

Our Board has unanimously approved and declared advisable and is recommending that our stockholders approve and adopt a proposed amendment to our Certificate of Incorporation to combine the outstanding shares of our Common Stock into a lesser number of outstanding shares, in substantially the form attached hereto as Appendix A, to effect an additional reverse stock split of all of our outstanding shares of Common Stock at a specific ratio within a range of one-for-two (1-for-2) to a maximum of a one-for-two hundred fifty (1-for-250), (the “Reverse Stock Split”), with the final decision of whether to proceed with the Reverse Stock Split, the effective time of the Reverse Stock Split, and the exact ratio of the Reverse Stock Split to be determined by our Board, in its sole discretion and without further action by the Company’s stockholders; provided, however, that our Board will not select a reverse split ratio that will result in us having fewer than 500,000 publicly held shares under the Nasdaq continued listing standards. The following table contains approximate information relating to our Common Stock immediately following the Reverse Stock Split under certain possible exchange ratios, based on share information as of June 18, 2025 (all share numbers are rounded down to the nearest whole share):

By approving the Reverse Stock Split, stockholders will approve the Reverse Stock Split at a specific ratio within the range described above as determined by the Board, as it determines to be in the best interest of the Company’s stockholders. The Board believes that stockholder approval of the range of reverse stock split ratios (as opposed to approval of a single reverse stock split ratio) provides the Board with maximum flexibility to achieve the purpose of the Reverse Stock Split, as discussed below, and therefore is in the best interests of the Company and its stockholders.

If our stockholders approve the Reverse Stock Split, and our Board decides to implement it, the Reverse Stock Split will become effective as of a date and time to be determined by the Board that will be specified in the certificate of amendment (the “Effective Time”). If the Board does not decide to implement the Reverse Stock Split within twelve (12) months from the date of the Annual Meeting, the authority granted in this proposal to implement the Reverse Stock Split will terminate.

The Reverse Stock Split will be realized simultaneously for all outstanding Common Stock. The Reverse Stock Split, if implemented, will affect all holders of Common Stock uniformly and each stockholder will hold the same percentage of Common Stock outstanding immediately following the Reverse Stock Split as that stockholder held immediately prior to the Reverse Stock Split, except for immaterial adjustments that may result from the treatment of fractional shares as further described below. The Reverse Stock Split, if implemented, will not change the par value of our Common Stock or the number of authorized shares of Common Stock. The Reverse Stock Split will also affect outstanding stock options and other stock-based awards, as described in “Principal Effects of Reverse Stock Split on Our Equity Plan and Equity Awards Thereunder” below.

In fixing the ratio, the Board may consider, among other things, factors such as the initial and continued listing requirements of Nasdaq Capital Market, the number of shares of our Common Stock outstanding, potential financing opportunities, and prevailing general market and economic conditions.

The Reverse Stock Split, if approved by our stockholders, would become effective upon the filing of the amendment to our Certificate of Incorporation with the Secretary of State of Delaware, or at the later time set forth in the amendment. The timing of the amendment will be determined by the Board based on its evaluation as to when such action will be the most advantageous to our Company and our stockholders. In addition, the Board reserves the right, notwithstanding stockholder approval and without further action by the stockholders, to abandon such an amendment and the Reverse Stock Split if, at any time prior to the effectiveness of the filing of the amendment with the Secretary of State of Delaware, the Board, in its sole discretion, determines that it is no longer in our best interest and the best interests of our stockholders to proceed.

The proposed form of amendment to our Certificate of Incorporation to affect the Reverse Stock Split is attached as Appendix A to this Proxy Statement. Any amendment to our Certificate of Incorporation to affect the Reverse Stock Split will include the Reverse Stock Split ratio fixed by the Board, within the range approved by our stockholders.

Our Common Stock is currently listed for trading on the Nasdaq Capital Market. As discussed above, the main objective for effecting the Reverse Stock Split, should our Board choose to effect one, would be to increase the per share price of the Common Stock to maintain compliance with the listing standards and policies of the Nasdaq Capital Market. There can be no assurance, however, that the market price of our Common Stock will remain at a level that will be sufficient to meet any requirements and policies of the Nasdaq Capital Market or that our Common Stock will remain listed on the Nasdaq Capital Market. In the event that we are not successful in maintaining the listing of our Common Stock on the Nasdaq Capital Market, we intend to seek a listing on another national securities exchange, which will also require that the per share trading price of our Common Stock be higher than our current per share trading price. In addition, our Board believes that, should the appropriate circumstances arise, effecting the Reverse Stock Split, could, among other things, help us to appeal to a broader range of investors, generate greater investor interest in the Company, and improve the perception of our Common Stock as an investment security.

As previously reported on our Current Report on Form 8-K, filed with the SEC on May 19, 2025, on May 16, 2025, we received notice from The Nasdaq Stock Market LLC (“Nasdaq”) that, because the closing bid price for the Company’s common stock has fallen below $1.00 per share for 30 consecutive business days, the Company no longer complies with the minimum bid price requirement pursuant to Nasdaq Listing Rule 5550(a)(2) (the “Minimum Bid Requirement”).

Nasdaq’s notice has no immediate effect on the listing or trading of the Company’s Common Stock. Pursuant to Nasdaq Listing Rule 5810(c)(3)(A), the Company is provided an initial compliance period of 180 calendar days, or until November 12, 2025, to regain compliance with the Minimum Bid Requirement. To regain compliance, the closing bid price of the Company’s common stock must meet or exceed $1.00 per share for a minimum of 10 consecutive business days prior to November 12, 2025.

If the Company does not achieve compliance with the Minimum Bid Requirement by November 12, 2025, the Company may be eligible for an additional 180 calendar days to regain compliance. To qualify, the Company would be required to meet the continued listing requirement for market value of publicly held shares and all other Nasdaq initial listing standards, with the exception of the Minimum Bid Requirement, and provide written notice of its intention to cure the minimum bid price deficiency during the second compliance period by effecting a reverse stock split if necessary. If the Nasdaq staff determines that the Company will not be able to cure the deficiency, or if the Company is otherwise not eligible for such additional compliance period, Nasdaq will provide notice that the Company’s common stock will be subject to delisting. In the event the Company receives notice that its common stock is being delisted, Nasdaq rules permit the Company to appeal any delisting determination by the Nasdaq staff. There can be no assurance that the Company will be able to regain compliance with the Minimum Bid Requirement or maintain compliance with the other listing requirements.

The Company intends to monitor the closing bid price of its common stock and may, if appropriate, consider implementing available options to regain compliance with the Minimum Bid Requirement.

The Reverse Stock Split could allow a broader range of institutions to invest in the Common Stock (namely, funds that are prohibited from buying stocks whose price is below certain thresholds), potentially increasing trading volume and liquidity of the Common Stock and potentially decreasing the volatility of the Common Stock if institutions become long-term holders of the Common Stock. The Reverse Stock Split could help increase analyst and broker interest in the Common Stock as their policies can discourage them from following or recommending companies with low stock prices. Because of the trading volatility often associated with low-priced stocks, many brokerage houses and institutional investors have internal policies and practices that either prohibit them from investing in low-priced stocks or tend to discourage individual brokers from recommending low-priced stocks to their customers. Some of those policies and practices may make the processing of trades in low-priced stocks economically unattractive to brokers. Additionally, because brokers’ commissions on low-priced stocks generally represent a higher percentage of the stock price than commissions on higher-priced stocks, a low average price per share of Common Stock can result in individual stockholders paying transaction costs representing a higher percentage of their total share value than would be the case if the share price were higher. Some investors, however, may view the Reverse Stock Split negatively because it reduces the number of shares of Common Stock available in the public market.

The Board believes that retaining our listing on the Nasdaq Capital Market is in the best interests of the Company and our stockholders and is crucial to stockholder value and liquidity and our long-term business prospects.

Our Board believes that stockholder adoption of several fixed reverse stock split ratios, as opposed to adoption of a single reverse stock split ratio, provides maximum flexibility to achieve the purposes of the Reverse Stock Split and, therefore, is in the best interests of the Company and its stockholders. In determining which of the approved fixed ratios to implement following the receipt of stockholder approval, the Board (or any authorized committee of the Board) may consider, among other things, factors such as:

The Board reserves the right to elect to abandon the Reverse Stock Split (including all of the fixed reverse stock split ratios), notwithstanding stockholder approval thereof, if our Board determines, in its sole discretion, that the Reverse Stock Split is no longer in the best interests of the Company and its stockholders. In making such determination, our Board will take into account certain factors including the expected trading prices for our Common Stock, actual or forecasted results of operations and the likely effect of such results on the market price of our Common Stock, as well as the factors described in the above paragraph.

If the Reverse Stock Split is approved by the Company’s stockholders, and if at such time the Board still believes that a reverse stock split is in the best interests of the Company and its stockholders, the Board will determine the ratio of the Reverse Stock Split to be implemented. The Reverse Stock Split will become effective as of the Effective Time. The Board will determine the exact timing and effectiveness of the filing of the certificate of amendment based on its evaluation as to when the filing would be the most advantageous to the Company and its stockholders. If the Board does not decide to implement the Reverse Stock Split within twelve (12) months from the date of the Annual Meeting, the authority granted in this proposal to implement the Reverse Stock Split will terminate.

Except as described below in the sections titled “Fractional Shares” and “Principal Effects of Reverse Stock Split on Our Equity Plan and Equity Awards Thereunder,” at the Effective Time, each whole number of issued and outstanding pre-Reverse Stock Split shares that the Board has determined will be combined into one post-Reverse Stock Split share (based on the Board’s final selection of the fixed ratio to be applied) will, automatically and without any further action on the part of our stockholders, be combined into and become one share of Common Stock, and each certificate that, immediately prior to the Effective Time represented pre-Reverse Stock Split shares, will be deemed for all corporate purposes to evidence ownership of post-Reverse Stock Split shares.

No fractional shares will be issued in connection with the Reverse Stock Split. Stockholders of record at the Effective Time of the Reverse Stock Split who otherwise would be entitled to receive fractional shares because they hold a number of pre-Reverse Stock Split shares not evenly divisible by the number of pre-Reverse Stock Split shares for which each post-Reverse Stock Split share is to be exchanged, will, in lieu of a fractional share, be entitled, upon surrender to the exchange agent of certificate(s) representing such pre-Reverse Stock Split shares (except as described below under “—Book-Entry Shares”), to a cash payment, without interest, in lieu thereof, as set forth in the certificate of amendment.

Stockholders should be aware that, under the escheat laws of the various jurisdictions where stockholders reside, sums due for fractional interests that are not timely claimed after the Effective Time may be required to be paid to the designated agent for each such jurisdiction. Thereafter, stockholders otherwise entitled to receive such funds may have to seek to obtain them directly from the state to which they were paid. Stockholders will not be entitled to receive interest for the period of time between the Effective Time and the date payment is received.

If the Reverse Stock Split is effected, stockholders who hold uncertificated shares (i.e., shares held in book-entry form and not represented by a physical stock certificate), either as direct or beneficial owners, will have their holdings electronically adjusted automatically by our transfer agent (and, for beneficial owners, by their brokers or banks that hold in “street name” for their benefit, as the case may be) to give effect to the Reverse Stock Split. Stockholders who hold uncertificated shares as direct owners will be sent a statement of holding from our transfer agent that indicates the number of post-Reverse Stock Split shares of our Common Stock owned in book-entry form.

As soon as practicable after the Effective Time of the Reverse Stock Split, stockholders will be notified that the Reverse Stock Split has been effected. We expect that our transfer agent will act as exchange agent for purposes of implementing the exchange of stock certificates. Holders of pre-Reverse Stock Split shares will be asked to surrender to the exchange agent certificates representing pre-Reverse Stock Split shares in exchange for certificates representing post-Reverse Stock Split shares in accordance with the procedures to be set forth in a letter of transmittal to be sent by us or our exchange agent. No new certificates will be issued to a stockholder until such stockholder has surrendered such stockholder’s outstanding certificate(s) together with the properly completed and executed letter of transmittal to the exchange agent. Any pre-Reverse Stock Split shares submitted for transfer, whether pursuant to a sale or other disposition, or otherwise, will automatically be exchanged for post-Reverse Stock Split shares. STOCKHOLDERS SHOULD NOT DESTROY ANY STOCK CERTIFICATE(S) AND SHOULD NOT SUBMIT ANY CERTIFICATE(S) UNTIL REQUESTED TO DO SO.

If our stockholders approve the Reverse Stock Split and the Board effects it, the number of shares of Common Stock issued and outstanding will be reduced, depending upon the ratio determined by the Board. The Reverse Stock Split will affect all holders of our Common Stock uniformly and will not affect any stockholder’s percentage ownership interest in the Company, except that as described above in the section titled “Fractional Shares,” record holders of Common Stock otherwise entitled to a fractional share as a result of the Reverse Stock Split because they hold a number of shares not evenly divisible by the Reverse Stock Split ratio will automatically be entitled to receive an additional fraction of a share of Common Stock to round up to the next

whole share. For those stockholders who hold shares with a brokerage firm, the Company intends to round up fractional shares at the participant level. The Reverse Stock Split will not affect any stockholder’s proportionate voting power (subject to the treatment of fractional shares).

The Reverse Stock Split will not change the terms of the Common Stock. Additionally, the Reverse Stock Split will have no effect on the number of shares of Common Stock that we are authorized to issue. At the time of this proposal, we have 2,000,000,000 authorized shares of Common Stock. After the Reverse Stock Split, the shares of Common Stock will have the same voting rights and rights to dividends and distributions and will be identical in all other respects to the Common Stock now authorized. Our outstanding shares of Common Stock will remain fully paid and non-assessable.

After the effective time of the Reverse Stock Split, we will continue to be subject to the periodic reporting and other requirements of the Securities Exchange Act of 1934, as amended (the “Exchange Act”).

Pursuant to the terms of our 2020 Stock Incentive Plan, as amended and restated (the “2020 Plan”) and the agreements governing equity awards thereunder, the Board or a committee thereof, as applicable, will adjust the number of shares of Common Stock available for future grant, the number of shares of Common Stock underlying outstanding awards, the exercise price per share of outstanding stock options, and other terms of outstanding awards issued pursuant to the 2020 Plan to equitably reflect the effects of the Reverse Stock Split. With respect to any such outstanding equity awards, the contemplated equitable adjustments will result in approximately the same aggregate exercise price being required to be paid under such stock options, and approximately the same value of shares of Common Stock being delivered upon exercise, vesting or settlement of such awards immediately following the Reverse Stock Split as was the case immediately preceding the Reverse Stock Split. Any fractional shares that would otherwise result from the Reverse Stock Split adjustments described above with respect to outstanding equity awards will be eliminated through rounding or as otherwise determined by the Board or a committee thereof in accordance with the terms of the 2020 Plan and award agreements thereunder.

Our registered holders of Common Stock hold some or all of their shares electronically in book-entry form with the transfer agent. These stockholders do not have stock certificates evidencing their ownership of the Common Stock. They are, however, provided with statements reflecting the number of shares registered in their accounts.

Stockholders who hold shares electronically in book-entry form with the transfer agent will not need to take action to receive evidence of their shares of post-Reverse Stock Split Common Stock.

Based upon the Reverse Stock Split ratio, proportionate adjustments are generally required to be made to the per share exercise price and the number of shares issuable upon the exercise of all outstanding options and warrants. This would result in approximately the same aggregate price being required to be paid under such options or warrants upon exercise, and approximately the same value of shares of Common Stock being delivered upon such exercise immediately following the Reverse Stock Split as was the case immediately preceding the Reverse Stock Split. The number of shares reserved for issuance pursuant to these securities will be reduced proportionately based upon the Reverse Stock Split ratio.

The proposed amendment to our Certificate of Incorporation will not affect the par value of our Common Stock. As a result, at the effective time of the Reverse Stock Split, the stated capital on our balance sheet attributable to the Common Stock will be reduced in the same proportion as the Reverse Stock Split ratio, and the additional paid-in capital account will be credited with the amount by which the stated capital is reduced. The per share net income or loss will be restated for prior periods to conform to the post-Reverse Stock Split presentation.

Under the Delaware General Corporation Law, our stockholders are not entitled to any dissenters’ or appraisal rights with respect to the Reverse Stock Split, and we will not independently provide stockholders with any such right.

The certificate of amendment will not affect the par value of our Common Stock, which will remain at $0.001 per share.

We have never declared or paid cash dividends on our capital stock. We currently intend to retain all of our future earnings, if any, to finance the operation, development and growth of our business. While the timing, declaration and payment of any future dividends to holders of our Common Stock fall within the discretion of our Board and will depend on our operating results, earnings, financial condition, the capital requirements of our business and other factors, our Board expects that the amount of future dividends, if any, would be adjusted accordingly to reflect the Reverse Stock Split.

Notwithstanding the decrease in the number of outstanding shares following the Reverse Stock Split, our Board does not intend for this transaction to be the first step in a “going private transaction” within the meaning of Rule 13e-3 under the Exchange Act.

The following is a summary of important tax considerations of the Reverse Stock Split. It addresses only stockholders who hold our Common Stock as capital assets. It does not purport to be complete and does not address stockholders subject to special rules, such as financial institutions, tax-exempt organizations, insurance companies, dealers in securities, foreign stockholders, stockholders who hold their pre-Reverse Stock Split shares as part of a straddle, hedge or conversion transaction, and stockholders who acquired their pre-Reverse Stock Split shares pursuant to the exercise of employee stock options or otherwise as compensation. This summary is based upon current law, which may change, possibly even retroactively. It does not address tax considerations under state, local, foreign and other laws. The tax treatment of a stockholder may vary depending upon the particular facts and circumstances of such stockholder. Each stockholder is urged to consult with such stockholder’s own tax advisor with respect to the tax consequences of the Reverse Stock Split.

The Reverse Stock Split is intended to constitute a reorganization within the meaning of Section 368 of the Internal Revenue Code of 1986, as amended. Assuming the Reverse Stock Split qualifies as a reorganization, a stockholder generally will not recognize gain or loss on the Reverse Stock Split, except to the extent of cash, if any, received in lieu of a fractional share interest. The aggregate tax basis of the post-Reverse Stock Split shares received will be equal to the aggregate tax basis of the pre-Reverse Stock Split shares exchanged therefor (excluding any portion of the holder’s basis allocated to fractional shares), and the holding period of the post- Reverse Stock Split shares received will include the holding period of the pre-Reverse Stock Split shares exchanged.

A holder of the pre-Reverse Stock Split shares who receives cash will generally be treated as having exchanged a fractional share interest for cash in a redemption by us. The amount of any gain or loss will be equal to the difference between the portion of the tax basis of the pre-Reverse Stock Split shares allocated to the fractional share interest and the cash received and generally should be capital gain or loss and generally would be a long-term gain or loss to the extent that the holder’s holding period exceeds twelve (12) months.

The foregoing views are not binding on the Internal Revenue Service or the courts. Accordingly, each stockholder should consult with their own tax advisor with respect to all of the potential tax consequences to them of the Reverse Stock Split.

We reserve the right to not file the certificate of amendment and to abandon any Reverse Stock Split (including all of the fixed reverse stock split ratios) without further action by our stockholders at any time before the effectiveness of the filing with the Secretary of State of the State of Delaware of the certificate of amendment, even if the authority to effect these amendments is approved by our stockholders at the Annual Meeting. By voting in favor of the Reverse Stock Split (including each of the fixed reverse stock split ratios), you are

expressly also authorizing the Board to delay, not proceed with, and abandon, the Reverse Stock Split (including all of the fixed reverse stock split ratios) and the certificate of amendment if it should so decide, in its sole discretion, that such actions are in the best interests of our stockholders.

Whether or not the Reverse Stock Split Proposal is approved, our Board may effect a reverse stock split pursuant to the May 2025 Approval.

Our officers and directors do not have any substantial interest, direct or indirect, in this proposal.

The affirmative vote of a majority of the outstanding shares of Common Stock entitled to vote on this proposal is required to approve the Reverse Stock Split Proposal. The affirmative vote of a majority of all votes cast by the holders of shares of Common Stock entitled to vote will be required for approval. Abstentions and broker non-votes, if any, will have no effect on the outcome of this proposal.

YOUR BOARD UNANIMOUSLY RECOMMENDS A VOTE “FOR” THE APPROVAL OF THE REVERSE STOCK SPLIT PROPOSAL.

Pursuant to the Dodd-Frank Wall Street Reform and Consumer Protection Act, enacted in July 2010, and related SEC regulations, we are providing our stockholders with the opportunity to cast an advisory vote on the compensation of our named executive officers as disclosed in this Proxy Statement in accordance with the compensation disclosure rules of the SEC. Our stockholders previously expressed a preference that we hold advisory votes on executive compensation on an annual basis, and our Board accordingly determined to hold such votes every year.

Our executive compensation programs are designed to reward our named executive officers for the achievement of short-term and long-term strategic and operational goals, while at the same time avoiding the encouragement of unnecessary or excessive risk taking. Stockholders are encouraged to read the “Executive Compensation” section of this Proxy Statement for a more detailed discussion of how our compensation programs reflect our objectives.

The Board believes that the Company’s executive compensation programs use appropriate structures and sound pay practices that are effective in achieving our core objectives. Accordingly, the Board recommends that you vote in favor of the following resolution:

“RESOLVED, that the Company’s stockholders approve, on an advisory basis, the compensation of the named executive officers, as described in the Company’s proxy statement for the Annual Meeting of Stockholders pursuant to Item 402 of Regulation S-K and other compensation disclosure rules of the Securities and Exchange Commission.”

The vote on this proposal is advisory and therefore not binding on us or our Board. Although the vote is non-binding, the Board will review the voting results, seek to determine the cause or causes of any significant negative voting, and take them into consideration when making future decisions regarding executive compensation programs.

The proposal to approve, on an advisory basis, the compensation of our named executive officers requires the affirmative vote of a majority of the Common Stock having voting power present in person or represented by proxy at the Annual Meeting. Abstentions are considered present and entitled to vote with respect to this proposal and will, therefore, be treated as votes “against” this proposal. Broker non-votes will have no effect on this proposal.

YOUR BOARD UNANIMOUSLY RECOMMENDS THAT THE STOCKHOLDERS VOTE “FOR” THE APPROVAL, ON AN ADVISORY BASIS, OF THE COMPENSATION OF OUR NAMED EXECUTIVE OFFICERS.

On [•], 2025, our Board, upon recommendation of the Compensation Committee, approved the fifth amendment and restatement of our 2020 Stock Incentive Plan (the “Fifth Amended Plan”), subject to the approval of our stockholders at the Annual Meeting. The 2020 Stock Incentive Plan was approved by our stockholders at our 2020 annual meeting of stockholders. Subsequently, the amended and restated 2020 Stock Incentive Plan was approved by our stockholders at our 2021 annual meeting of stockholders, the second amended and restated 2020 Stock Incentive Plan was approved by our stockholders at our 2022 annual meeting of stockholders, the third amended and restated 2020 Stock Incentive Plan was approved by our stockholders at our 2023 annual meeting of stockholders, and the fourth amended and restated 2020 Stock Incentive Plan was approved by our stockholders at our 2024 annual meeting of stockholders (collectively referred to as the “Plan” in this proposal). The Board is requesting stockholder approval of the Fifth Amended Plan.

The Board believes that equity awards are a key element underlying its ability to retain, recruit and motivate key personnel who are critical to our ability to execute successfully and implement our growth plans. After reviewing the 2020 Plan, the Board has determined that the current share reserve available for awards under the 2020 Plan is insufficient and limits the Board’s ability to provide equity incentives that align the interests of our directors, executives and employees with those of our stockholders and limits our ability to attract and retain talented personnel. Approval of the Fifth Amended Plan by our stockholders will allow us to grant stock options, restricted stock unit awards and other awards at levels determined appropriate by our Board or Compensation Committee.

The Fifth Amended Plan contains the following material changes from the Plan:

The following summary of the principal features of the Fifth Amended Plan is qualified in its entirety by the full text of the Fifth Amended Plan, a copy of which is attached to this Proxy Statement as Appendix B.

The Fifth Amended Plan, approved by our Board and submitted for stockholder approval, includes an increase in the number of shares available for issuance of equity incentive awards by the Company by 20,000,000 shares.

The Fifth Amended Plan contains the following important compensation and governance best practices:

The following table provides certain information regarding our equity incentive program:

To provide the Company the flexibility to responsibly address our future equity compensation needs, we are requesting that stockholders approve the Fifth Amended Plan to make an additional 20,000,000 shares available for grant. Grant levels for the preceding three (3) fiscal years have averaged 191,805 shares per year.

The following table shows our key dilution metrics over the last three years:

When considering the number of shares authorized for issuance under the Fifth Amended Plan, the Compensation Committee reviewed, among other things, the potential dilution to the Company’s current stockholders as measured by burn rate, dilution and overhang, projected future share usage and projected future forfeitures. The projected future usage of shares for long-term incentive awards under the Fifth Amended Plan was reviewed under scenarios based on a variety of assumptions. The Compensation Committee is committed to effectively managing the number of shares reserved for issuance under the Fifth Amended Plan while minimizing stockholder dilution.

The purpose of the Fifth Amended Plan is to assist management in the recruitment, retention and motivation of employees, outside directors and consultants who are in a position to make material contributions to our long-term success and to the creation of stockholder value. The Fifth Amended Plan offers a significant incentive to encourage our employees, outside directors and consultants by enabling those individuals to acquire shares of our Common Stock, thereby increasing their proprietary interest in the growth and success of our Company.

The Fifth Amended Plan provides for the direct award or sale of shares of Common Stock (including restricted stock), the award of stock units and stock appreciation rights and the grant of both incentive stock options to purchase common stock intended to qualify for preferential tax treatment under Section 422 of the Code and nonstatutory stock options to purchase Common Stock that do not qualify for such treatment under the Code.

All employees (including officers) and directors of the Company or any subsidiary and any consultant who performs services for the Company or a subsidiary are eligible to purchase shares of Common Stock and to receive awards of shares or grants of nonstatutory stock options, stock units and stock appreciation rights. Only employees are eligible to receive grants of incentive stock options.

As of June 18, 2025, we (including our affiliates) had approximately 17 full-time employees and 5 non-employee directors, all of whom are eligible to receive awards under the Fifth Amended Plan. We also engage consultants from time to time who are eligible to receive awards under the Fifth Amended Plan.

The Fifth Amended Plan is administered by the Compensation Committee of our Board. Subject to the limitations set forth in the Fifth Amended Plan, the Compensation Committee has the authority to determine, among other things, to whom awards will be granted, the number of shares subject to awards, the term during

which an option, stock unit or stock appreciation right may be exercised and the rate at which the awards may vest or be earned, including any performance criteria to which they may be subject. The Compensation Committee also has the authority to determine the consideration and methodology of payment for awards.

The Compensation Committee, our Board and any of their designees do not have the authority to: (i) amend the terms of an outstanding option or stock appreciation right to reduce its exercise price, or (ii) cancel outstanding options or stock appreciation rights with an exercise price above the then-current fair market value per share in exchange for another option, stock appreciation right with a lower exercise price or for other award or for cash, unless the stockholders of the Company have previously approved such an action or if the action relates to a capitalization adjustment under the terms of the Fifth Amended Plan.

Subject to adjustment for certain changes in our capitalization, the aggregate number of shares of our common stock that may be issued under the Fifth Amended Plan will not exceed 21,303,334 shares, which is the sum of (i) 36,667 shares approved at the Company’s 2020 annual meeting of stockholders, plus (ii) 66,667 shares approved at the Company’s 2021 annual meeting of stockholders, plus (iii) 133,333 shares approved at the Company’s 2022 annual meeting of stockholders, plus (iv) 66,667 shares approved at the Company’s 2023 annual meeting of stockholders, plus (v) 1,000,000 Shares approved at the Company’s 2024 annual meeting of stockholders, plus (vi) 20,000,000 Shares approved at the Company’s 2025 annual meeting of stockholders, plus (vii) the number of unallocated shares remaining available for grant under the Plus Therapeutics, Inc. 2014 Equity Incentive Plan, as amended (the “2014 Plan”) as of the effective date of the Plan, plus (viii) the Predecessor Plan’s Returning Shares (as defined below), as such shares become available from time to time.

The term “Predecessor Plan’s Returning Shares” refers to the following shares of our Common Stock subject to any outstanding stock award granted under the 2014 Plan: (i) any shares subject to such stock award that are not issued because such stock award expired or otherwise terminated without all of the shares covered by such stock award having been issued, and (ii) any shares issued pursuant to such stock award that are forfeited back to us because of a failure to vest.

The number of shares that may be delivered in the aggregate pursuant to the exercise of incentive stock options granted under the Fifth Amended Plan will not exceed 21,303,334 shares, to the extent allowable under Section 422 of the Code, any shares that become available for issuance under the Fifth Amended Plan discussed below as a result of forfeiture or termination of awards. These limitations, and the terms of outstanding awards, shall be adjusted as appropriate and equitable in the event of a stock dividend, stock split, reclassification of stock or similar events.

If stock units, options, or stock appreciation rights are forfeited or terminate for any other reason before being settled or exercised, or if restricted shares are forfeited, then the corresponding shares will again become available for awards under the Fifth Amended Plan. If stock units are settled or stock appreciation rights are exercised, then, only the number of shares settled or exercised shall reduce the number of shares available under the Fifth Amended Plan. Shares withheld to satisfy the grant price, exercise price or tax withholding obligation pursuant to an award will not again become available for awards under the Fifth Amended Plan.

Under the Fifth Amended Plan, the sum of any cash compensation, or other compensation, and the value (determined as of the grant date in accordance with Financial Accounting Standards Board Accounting Standards Codification of Topic 718, or any successor thereto) of awards granted to any of our non-employee directors as compensation for services as a non-employee director during any calendar year may not exceed $500,000 (increased to $700,000 in the calendar year of his or her initial service).

The terms of any grants of stock options under the Fifth Amended Plan will be set forth in a stock option agreement to be entered into between the Company and the recipient. The Compensation Committee will determine the terms and conditions of such option grants, which need not be identical. The Compensation Committee may modify, extend or renew outstanding options but the Compensation Committee may not modify outstanding options to lower the exercise price or cancel options in exchange for cash, for options, for stock appreciation rights with a lower exercise price or for another award, other than in connection with a corporate transaction, without stockholder approval.

The exercise price of each option will be set by the Compensation Committee, subject to the following limits. The exercise price of an incentive stock option cannot be less than 100% of the fair market value of a share of Common Stock on the date the option is granted, and in the event an option recipient is deemed to be a ten percent (10%) owner of our Company or one of our subsidiaries, the exercise price of an incentive stock option cannot be less than 110% of the fair market value of a share of Common Stock on the date the option is granted. The exercise price of a nonstatutory stock option cannot be less than 100% of the fair market value of a share of the Company’s Common Stock on the date the option is granted. The maximum period in which an option may be exercised will be fixed by the Compensation Committee and included in each stock option agreement and cannot exceed ten (10) years in the case of an incentive stock option (and in the event an option recipient is deemed to be a ten percent (10%) owner of our Company or one of our subsidiaries, the maximum period for an incentive stock option granted to that person cannot exceed five (5) years). In addition, no option recipient may be granted incentive stock options that are exercisable for the first time in any calendar year for our Common Stock having a total fair market value (determined as of the option grant) in excess of $100,000.

The exercise price for the exercise of a stock option may be paid in cash or, to the extent that the stock option agreement so provides, by surrendering shares of Common Stock, by a broker-assisted cashless exercise procedure, by a net exercise arrangement, by delivering a full-recourse promissory note or in any other form that is consistent with applicable laws, regulations and rules. Options generally will be nontransferable except in the event of the option recipient’s death, but the Compensation Committee may allow the transfer of nonstatutory stock options through a gift or domestic relations order to the option recipient’s family members.

Stock options granted under the Fifth Amended Plan generally must be exercised by the optionee before the earlier of the expiration of such option or ninety (90) days after termination of the optionee’s employment, except that the period may be extended based on certain events including death and termination of employment due to disability. Each stock option agreement will set forth the extent to which the option recipient will have the right to exercise the option following the termination of the recipient’s service with us, and the right to exercise the option of any executors or administrators of the award recipient’s estate or any person who has acquired such options directly from the award recipient by bequest or inheritance.

The terms of any awards of restricted shares under the Fifth Amended Plan will be set forth in a restricted share agreement to be entered into between the Company and the recipient. The Compensation Committee will determine the terms and conditions of the restricted share agreements, which need not be identical. A restricted share award may be subject to vesting requirements or transfer restrictions or both. Restricted shares may be issued for such consideration as the Compensation Committee may determine, including cash, cash equivalents, full-recourse promissory notes, past services and future services. Award recipients who are granted restricted shares generally have all of the rights of a stockholder with respect to those shares. Holders of restricted shares must invest any cash dividends received into additional restricted shares.

The terms of any awards of restricted stock units under the Amended Plan (referred to as “stock units” in the Fifth Amended Plan document) will be set forth in a restricted stock unit agreement to be entered into between the Company and the recipient. The Compensation Committee will determine the terms and conditions of the restricted stock unit agreements, which need not be identical. Restricted stock units give an award recipient the right to acquire a specified number of shares of Common Stock or, at the Compensation Committee’s discretion, cash, or a combination of Common Stock and cash, at a future date upon the satisfaction of certain vesting conditions based upon a vesting schedule or performance criteria established by the Compensation Committee. Restricted stock units may be granted in consideration of a reduction in the award recipient’s other compensation, but no cash consideration is typically required of the award recipient. Unlike restricted shares, the stock underlying restricted stock units will not be issued until the stock units have vested, and recipients of restricted stock units generally will have no voting or dividend rights prior to the time of issuance of any Common Stock upon settlement.

The terms of any awards of stock appreciation rights under the Fifth Amended Plan will be set forth in an agreement to be entered into between the Company and the recipient. The Compensation Committee will determine the terms, conditions and restrictions of any such agreements, which need not be identical.

A stock appreciation right generally entitles the award recipient to receive a payment upon exercise of the right equal to the amount by which the fair market value of a share of Common Stock on the date of exercise exceeds the value of a share of Common Stock on the date of grant. The amount payable upon the exercise of a stock appreciation right may be settled in cash or by the issuance of shares of Common Stock. The Compensation Committee may not modify outstanding stock appreciation rights to lower the exercise price or cancel stock appreciation rights in exchange for cash or for options or stock appreciation rights with a lower exercise price or for another award, other than in connection with a corporate transaction, without stockholder approval.

An award may be made subject to the attainment of performance goals for a specified period of time relating to performance criteria including, but not limited to one or more of the following performance criteria, either individually, alternatively or in any combination, applied to either us as a whole or to a business unit or subsidiary, either individually, alternatively or in any combination, and measured either annually or cumulatively over a period of years, on an absolute basis or relative to a pre-established target, to previous years’ results or to a designated comparison group or index, in each case as specified by the Compensation Committee in the award: (i) cash flow, (ii) earnings per share, (iii) earnings before interest, taxes and amortization, (iv) return on equity, (x) total stockholder return, (vi) share price performance, (vii) return on capital, (viii) return on assets or net assets, (ix) revenue, (x) income or net income, (xi) operating income or net operating income, (xii) operating profit or net operating profit, (xiii) operating margin or profit margin, (xiv) return on operating revenue, (xv) return on invested capital, (xvi) market segment shares, (xvii) costs, (xviii) expenses, (xix) achievement of target levels of discovery and/or development of products or services, including but not limited to research or regulatory achievements, (xx) third party coverage and/or reimbursement objectives, (xxi) test volume metrics, (xxii) objective customer indicators (including, without limitation, customer satisfaction), (xxiii) improvements in productivity, (xxiv) attainment of objective operating goals, (xxv) objective employee metrics or (xxvi) any other measures of performance selected by the Compensation Committee. The Compensation Committee will appropriately adjust any evaluation of performance under a qualifying performance criteria for a performance period: (a) to exclude asset write-downs, (b) to exclude litigation or claim judgments or settlements, (c) to exclude the effect of changes in tax law, accounting principles or other such laws or provisions affecting reported results, (d) to exclude accruals for reorganization and restructuring programs, (e) to exclude any extraordinary nonrecurring items as determined under generally accepted accounting principles and/or in managements’ discussion and analysis of financial condition and results of operations appearing in our annual report to stockholders for the applicable year, (f) to exclude the dilutive and/or accretive effects of acquisitions or joint ventures, (g) to assume that any business divested by the Company achieved performance objectives at targeted levels during the balance of a performance period following the divestiture, (h) to exclude the effect of any change in the outstanding shares of our Common Stock by reason of any stock dividend or split, stock repurchase, reorganization, recapitalization, merger, consolidation, spin-off, combination or exchange of shares or other similar corporate change or any distributions to our Common Stock other than regular cash dividends, (i) to exclude the effects of stock based compensation, (j) to exclude costs incurred in connection with potential acquisitions or divestitures that are required to be expensed under generally accepted accounting principles and (k) to make other appropriate adjustments selected by the Compensation Committee. If applicable, the Compensation Committee will establish the goals before results are substantially certain and will determine and certify, for each award recipient, the extent to which the qualifying performance criteria have been met.

The Board may amend or terminate the Fifth Amended Plan at any time, but an amendment will not become effective without the approval of our stockholders to the extent required by applicable laws, regulations or rules. No amendment or termination of the Fifth Amended Plan will affect an award recipient’s rights under outstanding awards without the award recipient’s consent. No incentive stock options may be granted under the Fifth Amended Plan after the tenth (10th) anniversary of the date the Fifth Amended Plan is adopted by the Board.

The Company may cancel any award or require the participant to reimburse any previously paid compensation provided under the Fifth Amended Plan or an award agreement in accordance with (i) any Company recoupment policy (including the Clawback Policy, as amended from time to time), (ii) any other agreement or arrangement

with a participant, or (iii) any right or obligation that the Company may have regarding the clawback of “incentive-based compensation” under Section 10D of the Exchange Act, and any applicable rules and regulations promulgated under that act.

In the event of a subdivision of the outstanding Common Stock or a combination or consolidation of the outstanding Common Stock (by reclassification or otherwise) into a lesser number of shares, a recapitalization, a spin-off or a similar occurrence, a declaration of a dividend payable in Common Stock or a declaration of a dividend payable in a form other than shares in an amount that has a material effect on the price of the shares, the Compensation Committee will make appropriate adjustments in the number and class of shares covered by outstanding awards and the exercise price of outstanding options and stock appreciation rights, the number and class of shares that may be issued pursuant to the exercise of incentive stock options, and the number and class of shares available under the Fifth Amended Plan.

In the event of a merger or other reorganization, subject to any acceleration provisions in the agreement relating to an award, outstanding awards will be treated in the manner provided in the agreement of merger or reorganization. That agreement may provide for the assumption of outstanding awards by the surviving corporation or its parent, for their continuation by the Company (if the Company is the surviving corporation), for the substitution by the surviving corporation or its parent of its own awards, or for the acceleration of the exercisability of awards followed by the cancellation of those awards. The agreement of merger or reorganization may also provide for the full exercisability or vesting and accelerated expiration of outstanding awards, cancellation of outstanding awards to the extent not vested or exercised prior to the effective time of the merger or reorganization in exchange for such cash consideration, if any, as the Compensation Committee may consider appropriate, or settlement of the intrinsic value of the outstanding awards in cash, cash equivalents or equity, followed by cancellation of the awards. The Company need not take the same action or actions with respect to all awards or portions thereof or with respect to all participants, and the Company may take different actions with respect to the vested and unvested portions of an award.

In its discretion, the Compensation Committee may provide in the award agreement governing an award or at any other time may take any action as it deems appropriate to provide for acceleration of the exercisability, vesting and/or settlement in connection with a change in control of the Company of each of any outstanding award or portion thereof upon such conditions, including termination of the participant’s service prior to, upon or following the change in control. In the absence of such provision in an award agreement or any action taken by the Compensation Committee, no acceleration will occur.

For purposes of the Fifth Amended Plan, a change in control generally means the occurrence of any of the following events: (i) a change in the composition of the Board occurs, as a result of which fewer than one-half (1/2) of the incumbent directors are directors who either had been directors on the date that is twenty-four (24) months prior to the date that the change in control could be deemed to occur, or were elected or nominated to the Board with the affirmative votes of at least a majority of the directors who had been directors on the date that was twenty-four (24) months prior to the date the change in control cold be deemed to occur and are still in office at the time of election or nomination, (ii) any person who, through the acquisition or aggregation of securities, becomes the beneficial owner of securities of the Company representing fifty percent (50%) or more of the combined voting power of the Company’s then outstanding securities ordinarily having the right to vote at elections of directors (subject to certain exceptions set forth in the Fifth Amended Plan); (iii) the consummation of a merger or consolidation of the Company with or into another entity or any other corporate reorganization, if persons who were not stockholders of the Company immediately prior to the merger, consolidation or other reorganization, own immediately after the merger, consolidation or other reorganization fifty percent (50%) or more of the voting power of the outstanding securities of each of the continuing or surviving entity and any direct or indirect parent corporation of such continuing or surviving entity; or (iv) the sale, transfer or other disposition of all or substantially all of the Company’s assets.

This is a brief summary of the federal income tax aspects of awards that may be made under the Fifth Amended Plan based on existing U.S. federal income tax laws. This summary provides only the basic tax rules. It does not describe a number of special tax rules, including the alternative minimum tax and various elections that may be